wikis

** http://www.teachertube.com/view_video.php?viewkey=51aeb480ecbd988cd8cc Good introductory video
 * More on wikis

http://bsc-ancients.wikispaces.com/ (sample)

http://www.wikispaces.com

http://www.wikispaces.com/site/for/teachers100K Free ad-free wikis for teachers