Actually the oldest person I know on LJ is shiva_kun but that's cause we've been friends since the ninth grade. We are now both 24. The person I know LJ that I met on LJ and still talk to is fishnet_vixen. I read her journal a long time ago and chatted with her, but that was when I had a different user name. Then I changed it to something else. The I changed it again. But we have remained friends. I can't exactly pinpoint how long ago that was...but it was a couple of years. I have a couple of friends on LJ who I've been friends with longer, but they don't come around much anymore.