Twitter is, of course, terribly popular, but it always got on my nerves a little bit. One of my biggest issues with it was that once the IM notifications went away one day, and never came back, there was no sensible way to watch it. The client apps are pretty much invariably terrible.
But! The newest beta of Adium, the MacOS IM client with the bird icon, has quite nice Twitter integration! So I'm giving it another try; if nothing else, I am now following just about everyone who is following me. Yay!
My Twitter is here.