In this case, two different sources (one the Thing 3 post from 23 Things On A Stick) and the other an email from a friend I'm doing a "Why are people online anyway" presentation for later this month.
They come from a company called Common Craft who mostly do work for various companies and other organizations - but they've got four great intro Web 2.0 videos.
- RSS in plain English
- Social bookmarking in plain English
- Wikis in plain English