Have you used concept mapping or mind mapping as part of your teaching strategies? MindMeister is a web site that allows you to create mind maps that can serve both as a teaching tool and a collaboration tool. The free version allows for up to 3 mindmaps per user as well as real time collaboration. Here is a quick overview from their YouTube page:
And here is an example of a live collaboration:
You can check out their site at www.mindmeister.com
More bells and whistles are available at different levels of subscriptions. We don't have any ties to MindMeister or any other products we demonstrate on this site. But if you think it may be useful for your teaching we want you to know about it!