I play on a MUSH*, and I was talking with a friend about people's LJs and soforth - and thus, the challenge was enjoined: find other players' LJs! This is made rather more difficult by the fact that I only have the meagerest of information on who the other people are, and that nobody I know of actually writes about what their character does in their journals. It's a fun challenge, since I've mostly had to go by "feel" of the prose style. The most interesting part has been seeing what the social web looks like - who knows/has friended whom, what sorts of emergent groups there are, that sort of thing. I've only been able to verify a few of my guesses, but they seem pretty good so far.
* No, I ain't gonna say who - but I think it should be pretty obvious.