If you're on one of these services, please please add me, because I have a really hard time finding the people I know in all the nooks and crannies of the Interweb. Despite its intention, Web 2.0 does not make it easier to keep track of peeps!
If I added you to my LJ Friends list and you have absolutely no idea who I am, it's most likely because I saw one of your entries on a mutual friend's page or on a community, liked it, and went to check out your journal. :)
If I had to sum myself up with one word, it would be "dichotomous." My friend Brendan sums me up with two words: "devil incarnate." (Remind me to put a hex on him.) The one word Kim (my other half) offers up is "impossible," which he says relates to the inability to sum me up in one word rather than me personally being impossible. Yeah, sure. He's just afraid if he comes straight out and says that I'm impossible, I'll hurt him while he's sleeping.
Way back when, I started an apparently-now-defunct community: matchingrebequa (You just have to visit to see what it is.) Damn Livejournal for taking the Match feature away!