Recently I've experimented a little with twitter, but so far I'm not a big fan.
I really don't grok people claiming the 140 char limit to be 'liberating'; to me it's just one big annoyance: if I don't have to say anything then I tend to shut up - and if there is something noteworthy that I would indeed like to share, then it's quite unlikely to fit into that dinky straightjacket format. (It's pretty obvious that I'm not a big SMS user either.)
Most of what I've seen of twitter feels like looking at JPEGs with quality level 1; sure, you can recognize that there's something on that picture but its nowhere near intelligible and and it hurts my eyes.
On the other hand, I do see uses for this kind of sparrowy chirping; for example, as a platform for quick updates about local speed cameras and the like I think it's very good.
Ambivalence, thy name is az...
nope, not for me. my twitter account is gone and i'm going back to literate communication.