I just joined Twitter. This has the possibility to be either:
a) Fun and useful. For when I'm out somewhere and see something I want to blog about, but don't have my laptop with me. I send random texts to my sister's cell about stuff I see, why not branch out?
b) Yet another online thing I join and ignore. Take Myspace, for example (I just heard Henny Youngman: "Take Myspace, please!"). Or Bebo. Or classmates.com. I will not join Facebook, mainly because a lot of people at my at-work knitting/crafting group keep pressuring me to do it. Also, I don't like that they won't let you see what you're joining until after you've joined. But I digress.
There's an option or a script or something to have your Twitter updates feed to your blog. If I find I'm actually using the service, I'll probably do that.