I have only once meet someone I knew in real life on the net and never meet anyone in real life that I might conceivably know (as in they are also in
SL, or members of one or another website).
The one time I meet someone from real life on the net was when I was putting random names from my past into a webpage search field and stumbled across one of my best friends from when I was a child. I sent them an e-mail that was somewhat vague, but with enough, certain, information and asked if they were that person. They were. I think I chased them from that website, though, as they didn't return again. heh, oh well.