Wii; £24.99; cert 3+; Ubisoft

If we're being honest, you probably already know if Dance on Broadway is for you. When you went to open this review you were almost certainly looking for one of two things: justification for a purchase already decided on (or perhaps already made), or justification for your disdain.

Last November Ubisoft released Just Dance to underwhelming reviews but some of the best sales figures ever achieved by a third-party publisher for the Wii. With Just Dance 2 pencilled in for an October release, Dance on Broadway is a straightforward gap-filler – a quick and easy title certain to generate some revenue while also helping build anticipation for the main event.

The gameplay is almost identical to Just Dance, with players mimicking the actions of on-screen dancers, while holding a Wiimote. Just as with the former title, this feels entirely inadequate. Good dancing requires the whole body to move in unison, yet the nature of the hardware means that Dance on Broadway can only ever judge your performance on the basis of one limb. Even this is not done well.

At one point early on, while getting to grips with the concept, I found myself standing perfectly still, yet repeatedly being scored "great" for movements I hadn't even made. Knowing this, it was hard to shake the feeling that all subsequent successes or failures were rather arbitrary and at times it felt as though accidental motions were just as likely to be rewarded as intended ones.

From a presentation standpoint the game looks fine, if hardly inspiring, though the silhouetted images that appear along the bottom of the screen to warn you what moves are coming up can be more confusing than helpful. In terms of depth, the game offers little – with 20 show tunes to choose from but no career mode and nothing to unlock.

Yet this game will appeal to fans of Just Dance, of show tunes, and of games that provide an excuse to get up and throw yourself around your front room. Lyrics are displayed during the songs to allow players to sing along and as a party game it will provide plenty of cheap giggles. Some people will love it. And they knew they would from the moment they saw the title.

Rating: 2/5

Apple has some competition from a slew of companies. But it made its design decisions in a vacuum: so why did it go for the features that it did, and do they matter more than others?

Here's a question: why is the screen of Apple's iPad 9.7in across? Why that size? Why not bigger? Or smaller?

If we examine this question, we may be able to figure out the answer to another question: how are the slew of tablets being released now (hello Samsung) going to fare in the market?

Consider what the iPad was going up against when it was being designed: the range of Windows-based tablet computers, which would have had screens in the 12in to 13in range; the Amazon Kindle, a dedicated e-reader, with a 7in screen; and the Kindle DX, launched in May 2009, which has a 9.7in screen. (There was also, of course, the smaller range of machines, bottoming out at the iPod Touch, with its 3.5in screen.)

Apple's engineering and design team will have played with all sorts of screen sizes, and they'll have compared the Kindle and Kindle DX screens to see which was the more satisfying in terms of user experience – because that's where Apple really sweats it, on the user experience. You can imagine Steve Jobs wandering around with prototypes with differently-sized screens, trying to figure out which was the ideal. Given a certain screen size, you get a certain battery life. Or vice-versa.

Apple plumped for 9.7in, with 1024x768 pixels, and stuck in a huge battery too, which is what has given the iPad its (alleged) 10-hour battery life. Though for once, that claim seems to be backed up by anecdotal reports around the web: the iPad really does seem to last through the day. (Using 3G, Apple says you'll get a nine-hour battery life.)

But that battery life is also the reason the iPad weighs more than other tablets: because it's got a big battery.

Now we come to all the other tablets, which have been built and launched in the aftermath of Apple's January announcement – and may well have been designed since January too.

Here comes Samsung; here too is Viewsonic, and Archos, and we even got an email from Binatone, one of the really old British consumer electronics names. It's offering the "HomeSurf" for £130: 7in screen, 800x480, resistive touch screen "with stylus", 2GB storage, Wi-Fi, Android (2.2 we assume, but it's not specified), MicroSD card slot, plays MP4, H.264, XVID. The claimed video playback time: 3 hours. Plus there's an 8in version for £180: 800x600, touchscreen with stylus, 2GB storage, video playback MP4, H.264 (but not XVID, apparently), video playback time 4 hours.

Toshiba has also launched a tablet, with a 10.1in screen (interesting) with Froyo; apparently the 16GB version will cost about £399 – making it a challenge to Apple (the 16GB iPad is £429).

Samsung, which has attracted a lot of attention with the announcement of its Galaxy Tab – whose specifications were well-known ahead of the launch, apart from the price, which then didn't get announced – might struggle to make a big impact. Why? Because of the price: Heise Online at IFA says that the price for the unlocked 16GB 7in Wi-Fi/3G Galaxy Tab will be about €800. And Expansys has (since this article went up) set the price for the 16GB unlocked version at £680.

Does that sound reasonable? Well, if you compare it to the 64GB Wi-Fi/3G iPad, which costs exactly the same amount in Euros, and only £19 more in the UK, then … no. The suggestion is that Samsung is actually letting the mobile carriers – which will be the only retail avenue – decide the price. Mobile carriers may be able to lower the up-front price through 3G contracts.

Next, battery life: the Samsung will manage seven hours of video playback, it's claimed: we'll have to see whether that's the case. And you do get a camera on the front and back, plus other little extras.

Tim Bray, formerly at Sun and now looking after various Android-y things at Google, has had an early hands-on with the Galaxy Tab. "The world still isn't sure just where it is that tablets are the right tool for the job," he notes (which echoes my own ponderings about the function of the iPad, before it was released).

His other thoughts on the product:

"It's got a phone but (at least on the pre-release model I used) you can't hold it up to your head, which is a good thing as that would look supremely dorky... Did I mention that the screen is beautiful? Also it feels really good in the hand and looks pretty nice, and is obviously in the first microsecond's glance not an iPad."

So what will he do with it?

"I know what I'll use the Galaxy Tab for: to show off Android. The big screen just makes everything easier to see and point at, and graphics look outstanding, and it passes from hand to hand easily. Showing off Android is part of my job and this will help me do my job better."

That leads him onto his thoughts about what tablets are for:

"Which leads to a general theory, reinforced by informal observation of hipsters with iPads in coffee shops: a tablet is, crucially, a more shareable computer. A laptop, with its fragile hinge-ware and space-gobbling keyboard, is just not comfy to share. A tablet is easier to bring to the café, easier to hand across the table or along the sofa, easier to seize in the heat of the moment, easier to hold up in triumph, easier to set aside when you need to meet someone's eyes."

Key question:

"How big a market is that? Anyone who says they know is lying."

At which we turn to Ray Chen, the president of Compal, one of the big Taiwanese computer assembly companies – which builds tablets for companies including Dell, Acer and Lenovo. He thinks sales of non-Apple tablets will "not exceed" 15m units in 2011, and that there will be a fearsome shakeout soon after as the market turns out to be tougher than expected. Compare that to Apple, which says that it sold 3.27m iPads in the three months since the device launched in April. Clearly, Apple works out as the biggest player in that market.

But come around again to that question at the top: why is the iPad screen the size it is? If Apple thought that 7in was the sweet spot for this, it surely would have built it that size. Ignore the lack of features; remember the Slashdot observation when the first iPod came out: "No wireless. Less space than a [Creative Labs] Nomad. Lame." But what the iPod did have was size (the Nomad was a giant compared to it) and battery life.

I think the same applies for tablets. The specs, and things like cameras, are all subsidiary to the main things that people want to do with tablets: browse on them and share them (per Bray) and use them for long periods without having to hunt around for a power source. True, it would be nice if we could browse for hours on end on our laptops, but the choice there seems to be between netbooks offering long battery lives but pokey screens and keyboards, or nice big laptop screens but unsatisfactory battery life.

And even for the former of those categories, things aren't going well:

"Chen also noted that Wintel netbook sales have recently been devoured seriously by tablet PCs and if the two firms [presumably Microsoft and Intel] do not consider dropping prices or improve performance, sales will continue to drop."

This chimes with something Jack Schofield posted at ZDNet: while sales of desktop and laptop PCs are rising towards 1m per day, "Gartner also sees diminishing sales of netbooks, which it calls mini-notebooks. Netbooks accounted for 20% of mobile PC sales at the end of last year, but Gartner expects it to fall to around 10% by late 2014."

Netbooks are even beginning to look like a brief spasm in personal computing's history; Apple's disdain for them, and its refusal to produce one in the face of analysts and press who thought it was cutting its own throat by not doing so, now looks well-placed. Certainly, better to be the leader in a sector like tablets than a follower in netbooks.

But until more people have bought and tried out these tablets, we're not going to know if a 7in screen can do the job – or if, as one ever so slightly suspects, it's the 9.7in measurement that actually does the job best.

Chen's forecast is definitely one to watch – and it will be interesting to see if tablets turn out to be a sort of computing flash in the pan, like netbooks are looking, or if they turn into the equivalent of the MP3 player, and carve out a whole new mode of use. And if the latter, the really interesting question will be: what's the best-selling screen size? And how long is "long enough" for the battery? And is there any other essential element to a tablet that guarantees sales?

Jon Sawer needs to upgrade his old but dearly loved radio and wants to buy a high-spec DAB radio

I'm about to reluctantly upgrade from my existing extremely old but dearly loved radio. I'm intending to spend as much as I can afford on a top range, high specification standalone DAB radio. You have in the past published many articles on the subject on the UK DAB radio format and how you consider this to be inferior to the European model being developed, and I don't really wish to make an error in my purchase when shopping around.
Jon Sawer

You can't really buy decent standalone radios any more, unless you want a portable of the sort often called a "kitchen radio". Above that are "tabletop radios" that usually include other functions. The main features are FM and DAB digital radios, a connection for an MP3 player (often an iPod dock), and internet or Wi-Fi radio. Some have CD players and some have hard drives for storing music files. Finally there are "lifestyle" or microsystems that are actually mini hi-fi units with separate speakers. You'll have to decide which kind of system best fits your needs, and your budget.

This diversity reflects changes in the way people listen to music.
Radio now comes from a variety of sources, including thousands of internet radio stations. Also, many people now listen to music files from their portable music players or PC hard drives, not just to CDs and cassette tapes. The most common factor is FM radio, because it's cheap and because FM radio's network coverage is still much better than DAB's.

Portable DAB/FM radios tend to be mono and have "retro" (old fashioned) designs. The top-of-the-range model in this class is the Pure Digital Evoke-2S (from about £130), which has a smart veneered finish. It's also a proper stereo radio, although the speakers are too close together to create much of a stereo effect. It has the usual telescopic aerial but you can unscrew it and use something more capable if you live in a weak signal area.

There's a very similar Pure Evoke-3 model (from £154), which can record to SD memory cards and also comes with a remote control. However, it doesn't say it's upgradeable to DAB+ (see below), so you'll need to check. A cheaper alternative is the "piano black" Roberts Sound 80 (£85), which has a downward-facing bass woofer of the sort more common on tabletop designs.

Tabletop radios are trending towards a boxy design exemplified by the Roberts MP43 Sound 43 (CD/DAB/FM/Dock, £180). The Monitor Audio AirStream 10 (£224) is a more stylish and distinctive unit that also includes Wi-Fi and Ethernet connections. Pure's challenger is the Avanti Flow Table-top Digital Music System (£228), which also has a downward facing 5.25 inch subwoofer. However, the one to beat is the award-winning Vita Audio R2i (Walnut finish, £280), which has a reputation for its sound quality.

Microsystems attempt to deliver hi-fi, or something close to hi-fi, without the overhead of having a large stack of units and speakers on stands. For a very long time, small silver Denon CD/radio receivers have been the ones to buy, though the line has been challenged by Onkyo and others in the value-for-money stakes. The Denon RCD M38 (up to £300) is the latest model, and it now supports USB playback and DAB+ as well as DAB and FM. It's also available for £200 without the two small SC-M37 speakers usually supplied. This allows you to spend a bit more on better speakers.

There are dozens of small bookshelf speakers on the UK market including the Q Acoustics 2010 and 2020, Tannoy F1 Custom, Monitor Audio BR1 and Mordaunt Short Aviano. They are heavily discounted if you shop around, though in the long run, it's better to buy from a dealer who will let you listen to them first. Most sound much better on stands, but you can use four generous blobs of Blu-Tack to lift each speaker off a shelf.
Sony also offers a lot of "mini hi-fi" systems at low prices. The Sony CMTBX77DBI (CD/DAB/FM/Dock, £130) provides the advantages of separate loudspeakers and room-filling sound for less than the cost of many portable radios.

I've quoted current prices from Amazon.co.uk for convenience, and this is also a good site for checking star ratings and user reviews. You can also use TestSeek.co.uk to find magazine and website reviews of most products before shopping around.

In terms of future-proofing your purchase, the main thing is to look for support for DAB+. This is the relatively new digital radio standard that is replacing the old and inefficient DAB system currently used in the UK. Of course, there are no plans to use DAB+ in the UK at the moment, and even DAB+ will never see the global adoption enjoyed by FM. However, it is painfully obvious that DAB is floundering in the UK, and DAB+ provides the chance to offer higher sound quality, more channels and lower transmission costs than DAB so ultimately it cannot be avoided.

This doesn't mean DAB would be phased out immediately: DAB+ is backwards-compatible so the two would co-exist while 10m DAB sets drop out of use. Before there's a switchover from FM to DAB, digital radio listening must reach 50%, and national coverage has to match FM coverage. There is zero chance of digital radio listening reaching 50% by 2013, let alone that being DAB digital radio. Indeed, the number of FM radios is still growing much faster than the number of DAB radios, because FM is also appearing in mobile phones and MP3 players. There's also very little chance of DAB matching FM coverage in time: that would require the BBC to spend more than £100m on building out the network. (The government isn't going to pay for it directly, and commercial radio doesn't have the money.)

But it may never happen. If the government thinks it can make perhaps 150m FM radios redundant then it's in for a very rude shock. (Technically, FM will never be switched off: the plan is to use it for "hyperlocal radio" – presumably schools, hospital radio, community stations etc.)

However, as I've pointed out before, Lord Carter's Digital Britain report said: "To prepare for any such change or additional upgrade we will work to ensure that digital radio receivers sold in the UK are at least compliant with the WorldDMB receiver profile 1; which includes DAB+ and DMB-A." This prepares the way for moving beyond DAB, though I suspect it had more to do with the European Broadcasting Union's desire to find a standard that would actually work across Europe.

You could, of course, wait for radios that support WorldDMB receiver profile 1 (PDF), but don't hold your breath.

New social network built inside iTunes fails to keep out the spammers, showing a curse of social media – even inside proprietorial walls

Apple chief Steve Jobs's trumpeting of the 160 million credit card holders on iTunes was a siren call to spammers. As if they needed any invitation.

The most common incidence of scamming on Apple's latest social venture, Ping, is the offering of free iPhones from a dodgy URL. These avatar-less lurkers are mostly hanging around Ping's more famous participants – Katy Perry, for instance.

As MacRumors points out, no credit card details are needed to sign up for an iTunes Store account – the requisite accreditation for joining Ping – which would appear the spammers' way in.

"[Ping] implements no spam or URL filtering," says internet security firm Sophos, adding that the service is "drowning in scams and spams".

And it appears that Ping has also received a touch of the early-day Twitter, musician Ben Folds last night saying that an account had been created in his name. Verified accounts, Mr Jobs? (And are you sure those were Jack Johnson's tour photos? Was that really Coldplay's Chris Martin on stage on Wednesday?)

Graham Clulely, senior technology consultant at Sophos, said: "We're used to survey scams like this being spread far and wide via sites like Facebook, but clearly the lack of filtering on Ping is making it a brand new playground for the bad guys to operate in.

"It's ironic that the most common scams on Ping right now revolve around Apple's own iPhone. It's safe to assume that Ping does incorporate some rudimentary filtering to prevent offensive messages from being posted, so hopefully Apple's security team can extend this to also block scam messages and malicious links. In the meantime, though, Ping users should be wary of believing what they read on the new service."

Remember back in 2009 when Twitter was plagued by spammers? This is what happened when the site announced a declaration of war on spam in October last year:

Sophos also say the iTunes 10 update fixes 13 "separate vulnerabilities" in the components used to render the iTunes interface.

Lobbying by London Mayor Boris Johnson has paid off once more - and put the city further forward in the open data stakes

Tube train, on time. Photo by fabbio on Flickr. Some rights reserved

Want to get the bus and underground timetables, in a zippy XML format? You can, right now, via the London Datastore.

As the page explains, "The data available in the attached zip file consists of almost 800 xml files, with each relating to a particular service i.e. one per tube line, bus route, riverboat route, dlr route etc. Each xml file contains the following data elements: StopPoints; RouteSections; Routes; JourneyPatternSections; Operators; Services; VehicleJourneys."

Getting this data out hasn't been a trivial task - and my understanding is that it's been down to persistent lobbying from the Mayor of London, Boris Johnson, himself.

This is another significant tranche of data to come out of TfL - an organisation that for years has been seen by developers and some within the Greater London Assembly as something of a black box; as one person put it to me, "you pour money in at one end and you get transport out at the other, but you're not allowed to see inside it." Previously, TfL released data about locations of bus stops, and then some real-time data about movements of tube trains - which led, you'll recall, to Matthew Somerville's live tube train map. (Unfortunately, the API for that has been suspended: it couldn't cope with 10m hits per week, and hasn't come back since June. Ahem, ahem, TfL.)

You can see all the London transport-related datasets via the London Datastore. With Johnson pushing it, though, light is starting to shine inside TfL.

By far the most successful demonstration of the power of making data free though has come from the London Cycle Hire scheme - where you can now get real-time information about availability of bicycles for hire, by location, in apps for Android and iPhone.

But if we can now add information about bus and tubes to apps like that, we're getting closer to the point where TfL really is being run for the citizens of London, rather than (as many bureaucracies are) for its staff. The distinction is a fine one - most organisations think of themselves as having their users' best interests at heart; the difference is that when you can get feedback, then the organisation may discover things about their users that they never knew.

There's still some way to go with TfL: for example, it collects data about how many cars pass particular points (using induction loops in the road) which is used for traffic light timing; that's data that many developers would love to get their hands, or processors, on. You never know: if the pressure continues, it might come too.

You might think that Boris Johnson's presence pushing this along is just a bit of grandstanding, but that wouldn't be correct. He's actually been in the vanguard of politicians introducing open data. If you have a long memory for public data-related stories, you'll recall that he did a rather neat end-run around the Labour administration's Home Office in 2008, when as part of his manifesto while running for the office of London mayor he declared that he would publish crime maps.

We were a little sceptical on the Free Our Data blog, although the blocking attitude of the police and the Information Commissioner's Office did nudge us towards Johnson's side.

Johnson did go on to publish them, and London has been in the forefront of cities which have tried to do innovative things with the data that its local government and authorities collect. First came the London Datastore, launched in January. Then came the datasets. And that brings us to the present day. For the many who don't live in London, this might all seem academic - but really the Datastore, and the political impetus behind it, are examples for the rest of the country that making data open and reusable actually can have a benefit. Would the Bike Scheme be as useful if you couldn't find out availability easily? Probably not. And once the TfL timetables have been processed, someone is sure to have a smart use for them.

Can't wait, personally. Overall, 2010 has already been a fantastic year - possibly the best ever - for making data free: first the London Datastore, then the Ordnance Survey OpenData release in April, and now the drive by central government to get both central and local government to publish data (soon to include the text of contracts) about spending. Results don't come much better than that.