Google Wave could be a great way to have a backchannel discussion in a course. In Wave you can play back the entire course of a conversation. This option could be useful for students who were absent from a class meeting to see how a conversation developed. Being able to add images, maps, and videos into a Wave makes Wave more than just a chat or email service. Online conversations could take on a new depth when more media is introduced.
DawsonITE is a blog devoted to Educational Technology. It's compiled by Rafael Scapin, Coordinator of Educational Technology at Dawson College in Montreal (Canada).