It's called Common Craft-Explanations In Plain English. They work with clients and create videos for-profit, but they also create basic educational videos on Web 2.0 technologies.
They have them for:
Blogs
Wikis
Social Networking
and
Social Bookmarking to name a few.
I find their videos to be very well done. In short videos, they explain the basics of each technology and how it can improve a user's online experience. If a student or teacher ever inquires about them, I recommend showing them this site as I don't think I've seen an introduction that has been as clear as these are.
My favorite video is the RSS video below.
~Krista Jacobson
