Christine Greenhow, a postdoc at the Social Networks Research & Creative Collaborative at the University of Minnesota, has done some very interesting research on the educational benefits of social networking sites. Check out the Media Release and the Video Release.
Educational Benefits of Social Network Sites
October 23, 2008 by Mark Warschauer
Papyrus News 
Hi Mark, nice to see you re-emerging on the social network. This article reports on an interesting study but oddly it doesn’t seem to be referenced or downloadable from the article. It seems similar to this one, have you seen it?
http://news.becta.org.uk/display.cfm?resID=38417
If you or one of your researchers has a link or reference to the source document it would be nice to see it here.
Wishing you all the best,
Vance