I found the following on Internet4Classrooms which I think is appropriate:
Web 2.0 is more about users and content than about surfing on the Internet. It's more like what can the Internet do for me as a creator, a collaborator, an active participant,
rather than a passive viewer of what is out there on the web.
Here is a video "What is Web 2.0?"
This web site also offers many valuable links for the classroom teacher.
I have also put a lot of information relating specifically to the use of blogs in the classrooms.
This is another look at why use blogs in the classroom environment.
Interesting slide show about using Web2 in the classroom.
Another idea I came across is a Random Ideas Generator to encourage higher-order thinking skills. It is simple and works like this:
Some good ideas in this video: