Twitter
http://www.emergingedtech.com/2009/06/6-examples-of-using-twitter-in-the-classroom/
http://www.readwriteweb.com/archives/how_one_teacher_uses_twitter_in_the_classroom.php
http://mashable.com/2010/03/01/twitter-classroom/
Facebook
http://www.onlinecollege.org/2009/10/20/100-ways-you-should-be-using-facebook-in-your-classroom/
http://www.collegedegree.com/library/college-life/15-facebook-apps-perfect-for-online-education
