I have always been a big fan of the free online encyclopedia Wikipedia. Wikipedia allows people to create entries in the encyclopedia. If you know more about what you just read on one of the pages you could edit it. I believe changes are reviewed by a committee before being published. I personally feel that Wikipedia takes democratization of information to the next level. This is truly an encyclopedia of the people, by the people, and for the people. However, they ran into problems when certain malicious people created entries which were not only factually incorrect by contained some disparaging remarks about individuals.
The New York Times reports that the "Anyone Can Edit" is changing. This demonstrates an interesting point in how a wonderful concept cannot be implemented in its pure form.