There was a site called Simler (http://simler.com http://simler.com) that attempted to do this. Its goal was to help you find new people who you might be friend

There was a site called Simler (http://simler.com http://simler.com) that attempted to do this. Its goal was to help you find new people who you might be friends with. It worked similar to Facebook or Twitter, via status updates. People tagged themselves with dozens or hundreds of arbitrary tags, then their engine would recommend people who share same interests. The challenge they faced was getting anybody to come to their site. You are not going to get people who feel they are already "friend full" there, which means your percentage of "abnormal" people (hey, I'm one - people who don't make friends easily). I think the algorithms will be easier to overcome than the problems with the self-selected population.