Social Networking for Scientists, Part N

It seems everyone is talking about social networking sites these days. There are interesting thoughts on Richard Grant’s and David Crotty’s blogs (read the comment threads as well). Many of those sites will die, others will adapt, but most, I think, will play a supporting role in a whole network of services surrounding…the actual scientific papers. For instance, surrounding TOPAZ-based PLoS papers, perhaps organized into Hubs. And papers from other journals that join into the system. Thoughts?