Wikipedia

I've recently discovered this free encyclopedia called Wikipedia. What is so awesome about it is that it can be edited and added to by anybody! Some people might think that this would turn it into crap, but the quality of information is on par with that of the World Book or any other similar encyclopedia, and it covers a far wided range of subjects, is more up to date... and if you see an error, you can fix it right away.

Very cool. Check it out.