I've been on Twitter since June 2007, but never even thought that it could be used for chess! I mostly use the service for connecting with other people in my line of work or reading news or just following "celebs" in the tech world who often post some interesting links. See, for instance, my post last week.
Now, in yet another step towards innovation, ChessVibes has recently signed up for Twitter and began tweeting. Their first tweet said, "Exploring Twitter (it's about time)". The editor describes the move as an experiment, but I hope they make it work and stick to it! Here are a couple of tips for them: (i) dial down on the advertising and (ii) be more frequent.
Two other chess fans I know of who are on Twitter are @SonOfPearl and ChessExpress' @ShaunPress. The Aussie and ex-weekend warrior Malcolm Treddinick is also there, but he's mostly tweeting about his pained life as a programmer (e.g. "And now we will play the new traditional game called 'fixing all the stuff I broke yesterday'. This is getting old, I have to say.")