TWITTER: I completely [heart] Twitter though maybe slightly less than I did before Drake was born - but that's just because I'm settling into a usage pattern, less self-conscious about what I put up there. One thing I really like about it - aside from building a large (by my standards) audience quickly, is how it works as a unified clearinghouse for stuff on work, music, family, culture, politics, whatever: bcz of the 140chr limit there'll be something else along in a minute so hopefully nobody following me gets too bored.
TUMBLR: After stalling on tumblr for a few months I'm right back into it - it turned out to be incredibly easy and convenient when I was frazzled and on paternity leave. I think, as with Twitter, I'm a little more comfortable with the Tumblr culture than I was.
BLOGS (WRITING): Blackbeard Blog is going very well - actually for that I regret moving it to Tumblr a little as I would like better archiving and blogroll functions (and am too crap to code them myself). The success of Blackbeard is almost wholly down to building an interested audience via Twitter. Freaky Trigger, meanwhile, is going well from the perspective of Popular but I feel underinspired for everything else - my other stuff is drawing energy away from that, which ought to be a higher priority since it's my main web presence.
BLOGS (READING): Twitter and Tumblr have mostly replaced my RSS browsing - I'm making an attempt to catch up. Don't get much sense of a "blogosphere" anywhere but maybe that's cause I'm not reading more than 3 or 4 sites on most themes.
COMMUNITIES: Loving the revival of Poptimists masterminded by Kat and Hazel. Zero interest in running any comms now, or indeed reading any bar Poptimists (and Diggerdydum when that sparks up again). They're just too high maintenance.
FACEBOOK: Completely dead to me, to the extent I tend to enormously underestimate how big and important it is for lots of other people. I probably check in once a month. The same goes for LinkedIn on a professional level. They both seem so... bitty. All these different groups and notes and walls and whatnot. I want to have another go with FB, for work reasons if nothing else.
LIVEJOURNAL: I use it for the occasional snippet of personal information (like this!), and for bitching behind a friendslock. Not doing much of either right now, so it's lying mostly fallow. Also, it's in general decline, everyone's leaving, blah blah. (Not actually sure how true this is.)
OTHER STUFF: I'm on Friendfeed and intend to play with it properly sometime: right now it seems a little soulless. Flickr I just use for family things. YouTube I browse but don't join in.