Next time you're in London and need a cab, you might like to try tweeting @tweetalondoncab for one. Richard Cudlip, Karl James and a small circle of tech-inclined cabbies have spent the last year building up a black cab service on Twitter, and while Cudlip says they don't handle more jobs than in their street-hailing days, it's the data the service generates that is the really interesting part.

There's now 100 cabbies using tweetalondoncab and nearly 7,000 followers, which means they are nearing a critical mass where the service starts getting really useful with enough cabs to match the number of punters. The drivers are self employed and tweetalondoncab is a voluntary, cooperative project, but the founders want to build it into a business and are looking for funding. They've already met Channel 4's 4ip.

So what's the real advantage? The account acts as an aggregator for requests, and cabbies can also flag up their location. Interestingly, isn't too far away from the courier update service idea started Twitter in thefirst place.

"We're getting more and more bookings, and the quality of bookings is better, with longer trips," said Cudlip, who says a few minor celebrities use the service because they find a direct message more discreet than flagging down cabs on the street. All the drivers are full licenced black cab drivers with 'The Knowledge' - and they now have a tweetalondoncab sticker in the window.

The surprise has been the real-time data, and the value of aggregating and sharing information about demand or surplus around the city - a tube line down for an hour, or too much of a queue at St Pancras. "We didn't even think of that when we started,"said Cudlip. "In two years, I'd like us to rival the black cab circuits like ComCab and RadioTaxis. We want more information to come in so we can share it with more people, and that information might be useful to other people in the same way TFL's data is shared."

The data challenge is quite a temptation for developers - three have already approached the team and suggested a mobile app - but there's a problem compiling data between a few hundred sole traders that has put developers off so far. Twitter has been the best solution to date, although a couple of developers are experimenting with Foursquare - setting themselves up as a virtual taxi rank and checking in when they are on duty.

That's pretty smart, but with clued-up, GPS smartphone-enabled cabbies spread across the city, surely that's just the start. It's a classic business ripe for disruption. Is anyone up for helping with the challenge?

Click here to view original article by the Guardian, Wednesday 4th August, 2010