Wikis in the library

Wikis begin to look like useful tools. There are a lot of uses for them in the library setting as well as outside the library. I thought the idea of a wiki for book reviews and comments would be great and helpful; also a community information one for a community calendar and activites; or a travel one to share restaurants, motels, and sites to see. One of the biggest problems I see would be the accuracy of a wiki. Depending on their use and intent, I think they would have to monitered in some way - too many tricksters and scammers out there!