
From Stephen Fry to 10 Downing Street, it seems that everyone is on Twitter these days, with research by eMarketer suggesting that the microblogging service will have 18 million users by the end of the year.
The iPhone is the perfect companion for Twitterers, allowing you to post updates from wherever you are. Here are 10 of the best applications for Twitter, ranging from common clients to more specialised software.

