The idea behind Scitable is a journal-quality, free science library. It’s peer-written and reviewed, and funded behind one of the largest science publishers in the world, Nature Publishing. But beyond the piles of information, there’s a social network of a few hundred thousand users.
http://thenextweb.com/socialmedia/2010/08/02/scitable-the-social-research-network-for-science-geeks/