I was totally and completely infatuated with Twitter back in '08 for 4 whole weeks. At my old job, we all got accounts and made each other laugh in the faculty room by tweeting across the room. Then we all got bored, and stopped. Then I got a Facebook account, and I never thought to go back to it.
I think the novelty wore off for me when I started trying to use it more socially - the character limit was, well, limiting. And when I saw how much other sites (again, like Facebook) added to their interfaces, I started thinking of Twitter as the ugly, boring stepsister to far cooler and capable sites.
I might be over that now. I liked the way that one of the Project Term groups used Twitter instead of a blog to update family, friends and faculty back at school - that was actually the impetus for my re-creating a Twitter account. And having looked at a certain dinovan's tweets, I see also the possibility for tweeting on a certain subject, but not having it be my primary social media. It seems best suited for quick points of information and reference, instead of conversation starting or more personal communication.
As an aside, I liked Note 2 on the assignment sheet - I've been lurking on Google Buzz trying to make sense of it and figure out if it's worth getting involved in. I do have a few contacts who are giving it the college try, hoping, I think, to see it eclipse Facebook. My own personal jury is still out.