I was sitting in on a session at the Educational Bloggers Network conference when I fired up iChat and opened the 'rendezvous' list. Almost immediately I got a note from Paul Bradley directing me to SubEthaEdit and telling me to join in on the conversation. This immediately added a new dimension to the session! Pretty nice icon too!

That was my first exposure to the tool and I found it easy to use and a great addition to this session. I like the fact that it doesn't seem to need much infrastructure (this might be great for our remote classrooms associated with our Med school). The other 'in class' tools that I am aware of are colligo and silicon chalk (and I used the Personal Response Systems in my Biology class to do surveys and quizzes).

http://cilt.berkeley.edu/people/ebaum/

http://dotlrn.org/