Check out the study reported here: http://www.intute.ac.uk/socialsciences/blog/2008/09/30/web-20-in-secondary-education/ by Paul Ayres. Although none of the statistics are surprising, this study is a great starting point for discussion as we try to kick our use of technology up a notch in our classrooms.
I spent today setting up an English 2 class discussion in Tapped In. At that site, the K12 campus is closed to all but those registered which makes it safe from anyone but us "owners" and "managers." Tapped In remains focused on teacher research, and so allows nothing on the K12 Campus that might endanger that focus. I have asked the tech leader at FLC to visit and to join the my class at the site, because he can check that I haven't violated School District policy. Further, he can help me set up a whole-class orientation seminar to be facilitated by Tapped In Help Desk people. Very friendly and helpful people!