Anyone tried 1Mind? It's based on typology (you take a quiz to type yourself, though it's kinda short) and the idea is you answer questions to help determine your compatibility with others as far as friendship is concerned. It seems there are a few notable people on the site, but I can't seem to find them. It's kinda not a good way to determine compatibility, but it seems great as a research tool, and it's kinda addicting to answer and see how others answer certain questions.
http://www.1mind.com
http://www.1mind.com