I heart Twitter as well. I think I'm a lot less deliberate/serious in my use of it than you though Tom - mostly I love the spontaneity of it, "this is in my head and needs to come out", or just for shooting shit with people. Actually it's the best social networking site for spontaneous meeting up IRL, sort of "who wants to go to the cinema/pub/art tonight". And it's so pressure-free w/r/t replying to people/getting replied to!

As with all these sites I hate the people on Twitter who NEVER EVER POST THEMSELVES and you don't know whether it's b/c they got an account but never got into it and forgot, or whether they're STILL THERE LURKING AND SPYING, taking everyone's thoughts and offering none of their own. Horrid people! Do not get the whole concept of lurking.

Facebook - rarely log in now b/c it's such a swamp of event invitations, group requests, constant messages from group promoters and so on. Still think it's v useful as a diary though.

Tumblr - don't think it has anything that I don't already get from Twitter or LJ or ILX. In the event that I get a paragraph-long thought about a band I'll usually go to the ILX thread where there's the best rate of reply. Still can never tell who says what on the ugly-ass Tumblr interface.

LJ - woo bitching behind flock! It feels almost PRIMITIVE.

Still can't get RSS feed to work. All it does is bookmark stuff.