I'm at the moment torn between thinking that this is a clever use of social networking and a parlor trick - but for what it's worth, President Obama will be holding a Twitter Town Hall at 1 PM Central time.  You can still submit questions to the President by tweeting with the hashtag #AskObama, and you can watch the event on a live stream at 1 PM at http://askobama.twitter.com/ .   Might be interesting.