If you have not checked out Flutter yet, I advise you do. They are a new site that only allows 26 characters per "flap" as opposed to twitter which allows 126 per "tweet."
It is a real time saver. Also they have some unique features that twitter does not.
To view the demo go to: http://www.youtube.com/watch?v=BeLZCy-_m3s
What will they think of next!
PS the video is a mockumentory. Enjoy!