Hey Doodlejump, I didn't mean to come off as a judgmental jerk. (Even though I am one.) I just meant to say that it made me feel really old, and that it isn't for me - which, as you say, could be said of any other social networking site!
I was surprised that he refused to divulge it over the air... he doesn't really strike me as a guy who dislikes attention. But then, maybe he uses it for "real life" friends and suchlike.