I love this.
If you are confused about Web2.0 take a look at this from YouTube.
As a teacher/librarian I do not encourage my young students to use Wikipedia simply because there are better sources for their research projects and with their luck they will hit Wikipedia on a day when someone is tampering with information. However, being a grad student sometimes it is necessary to use Wikipedia and sometimes you can find wonderful stuff. I never knew what a mind or concept map was until my last grad class when I had to produce one. The reason I am going on and on about concept maps is that I found a wonderful one describing Web2.0 in Wikipedia.
Check it out at: http://en.wikipedia.org/wiki/Web_2.