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. Yo
![How to hail a London cabbie using Twitter](https://cdn-ak-scissors.b.st-hatena.com/image/square/0293de779e6f59cc8d3df6e15d02e446bc05d82a/height=288;version=1;width=512/https%3A%2F%2Fassets.guim.co.uk%2Fimages%2Feada8aa27c12fe2d5afa3a89d3fbae0d%2Ffallback-logo.png)