Who’s your friend?

I just looked through my friend list and I see some people who's name I recognize but don't know exactly the context where I knew them from, and then there are mysteriously who I really don't think I've ever known, so I can't remember how they got there.

I was discussing with some people at the party how we are going to soon have a new word to distinguish a 'real' friend from a 'facebook' (or other social network) friend, as well as a term to distinguish a 'real' social network from one on the computer. See one of my favorite new terms, Retronym.