I know a large number of "experts" (and also experts) have done analysis on social networking sites. One of my team members is doing an analysis for recruiting. Right now, he's planning on looking into LinkedIn, Orkut, MySpace, Facebook and Xing. I know there's some popular wisdom out there regarding what the best sites are, but at the same time, all kinds of people are twittering and I think it's a colossal waste of time (sorry, twitterers). I just don't care what people are grocery shopping for.

Anyway, I wanted to ask what sites you feel are the best for making connections (whether there's an implied business connection like on LinkedIn or at least a social connection with enough profile data to be used for business purposes like the employment section of Facebook profiles). Any ideas of what else we should be looking at? Any existing analysis or white papers that you found impressive or informative?

Totally self-serving, I know, but a girl's got to use her blog for herself sometimes.