Several Twitter accounts all of which I deleted. Facebook, which I used three times then deleted. I'm just about to set up an identi.ca and I'll definitely be all over disapora* when it's released, but that is shaping up to be so much more than just a social networking site. As far as I can see, diaspora* might change the way we think about the web completely.
Also, Facebook is just beyond horrible when it comes to privacy.