Earlier today the news broke that TweetDeck, the most popular Twitter desktop client, is coming to the iPhone. I tracked down TweetDeck investor John Borthwick of betaworks at the 140 Characters Conference in New York City. Sure enough, he has a version of the new TweetDeck app on his iPhone (which just hit the iTunes store). He was kind enough to give me a demo, which I captured with a Flip video camera. He showed how TweetDeck on the iPhone handles different groups (which filter Tweets by followers or topic), as well as most of the other features as well. These include integration with Twitpic and yFrog for uploading pictures, integration with bit.ly (another betaworks company) for shortening links, and a GPS feature which lets you Tweet out your location. Not only that, but TweetDeck is pushing out an entirely new desktop client today.