Educational Benefits Of Social Networking Sites Uncovered: "The study found that, of the students observed, 94 percent used the Internet, 82 percent go online at home and 77 percent had a profile on a social networking site. When asked what they learn from using social networking sites, the students listed technology skills as the top lesson, followed by creativity, being open to new or diverse views and communication skills."
Interesting piece of research from the University of Minnesota on the positive aspects of use of social networking sites. They've come in for a fair bit of flak over the last year or so... but the fact that people are motivated enough to participate, create, share, think and learn together in this informal way has got to be more than something you can write off as 'flavour of the month'. Worth bookmarking and tracking down the original research if you're trying to make a case for more personalised learning systems.