Doug Peterson introduced me to Michael Wesch's video about Web 2.0 at the RCAC Symposium last year where it was used to introduce Will Richardson. Incidentally, I have heard that Will will be a featured speaker at the Ontario Association for Mathematics Education Annual Conference next May.
Wesch's videos explore mediated culture, seeking to merge the ideas of Media Ecology and Cultural Anthropology. He is currently working on an ethnography of YouTube.
Today, I was the two millionth person to see this video about what post-secondary students are like:
Here is the original video that I mentioned. It is a fantastic introduction to what Web 2.0 is (much better that Wikipedia's technical talk about CSS and APIs).