Thanks to Tiaan for sending us the link, the Kansas State University students for creating it and YouTube for hosting it
[coolplayer width="420" height="360" ] This is a very creative movie giving an overview of Web2.0[/coolplayer]
Here are two other decent basic videos that explain the elements of Web 2.0…

http://www.youtube.com/watch?v=nsa5ZTRJQ5w
http://www.youtube.com/watch?v=0LzQIUANnHc

Enjoy!