San Francisco's city council has opened up its data to the world, so anyone can use it to build useful - or useless  - tools and applications. We've seen apps to help you find your route home on the BART, apps to guide you to the nearest recycling centre, apps to help parents find child-friendly parks - even an app to help you choose the restaurant nearest you with the fewest cockroaches.

There's a few reasons why this is a Good Thing:

1. "Many brains" means that we have (potentially) several million smart, motivated citizens coming up with new ideas for using public data to help their fellow citizens live safer, healthier, greener, maybe even happier lives.
2. "Many hands" means that we end up with valuable and useful apps that the public bodies would never have the money or time to create.
3. It's our data - we paid for it to be collected, so why shouldn't we have the right to use it any way we like? (This makes it all the more depressing that here in the UK, the Post Office charges people to use the postcode database National Rail Enquiries shuts down the wonderful MyRail Lite just so it can flog its own iPhone app. And while we're at it - why doesn't all that Ordinance Survey data belong to us?)
4. The kind of apps that people find most useful may help policymakers to understand more about what we actually care about. Actions speak louder than words, and seeing how many people are using an app may give some idea of the issues that people care about. This kind of meta data might be one of the most valuable unexpected emergent effects of all this.

Over here in the UK, we're way behind. Directgov opened up their data to developers earlier this year via the Directgov Innovate project but it's been a pretty disappointing show so far. It's not clear where the "streams" that one needs actually come from. I couldn't see any, and most of the rather paltry total of 13 apps created so far seem to rely on scraping sites - leaving developers to format and structure data themselves.

I'd love to see things improve. In London, for example, the natural choice would be to open up transport data. That's pretty structured and really useful to citizens. I have no idea if TFL allows use of their data for free, but if not, they damn well should. Malcolm Barclay launched a couple of decent-enough iPhone apps for Londoners, but they're far from perfect. And they're both iPhone only - so no help to people on other platforms (excuse the pun).

What else might help? Well, besides relying on the efforts of concerned geeky citizens, I think that this is one space where brands might step in and provide real value. Surely HSBC's vast marketing budget could pay for a suite of handy free apps for travellers, rather than flogging to death their tired-looking Global/Local campaign?

Cheap, easy, viral and (gasp!) actually useful? Surely that's a winner.