I've never been a big fan of Twitter.
Unfortunately, it seems like it is the new Facebook when it comes to instant communication

I really like Twitter and think it can be used for some interesting/useful things. I think the Twittersphere is extremely fragmented, however, so it's hard to say what its overall influence will be. I use the site frequently (I would say I use Twitter more than Facebook) and have found it to be a really efficient way of finding out what's going on in the local community as well as on a grander scale.