If you like OpenCourseWare and Facebook, you need to check out CourseFeed.
CourseFeed started out as a virtual classroom app that supported Blackboard announcements and content, but it is growing into much more. Currently CourseFeed allows anyone on Facebook to add OCW courses from Stanford, Notre Dame, and Utah State University. The class wall allows anyone to discuss the course materials. CourseFeed is a simple concept, and yet a big step toward personalized, lifelong learning!
Check it out here: http://apps.facebook.com/coursefeed/?display=landingPage