Recently, I found two additional videos done by Lee and the CommonCraft people, titled: "Social Networking in Plain English" and "Wikis in Plain English" I'm embedding them into this blog post below, so you can just click on them and watch them from this blog. (Remember embedding of media we talked about a few weeks ago with the Simpson's Slide Show!)
Social Networking in Plain English
Wikis in Plain English
I think all three of these videos are a great way to introduce these concepts to teachers and to students in your classes. They are also a great refresher to keep around when you forget the basic concepts in each of these areas.