Whyapedia?

The more I read and learn about citizen-based knowlege sites like Wikipedia, the more I wonder why in the world people have the need to express their thoughts, ideas and knowleged so publically.
I see how this vast and public sharing of knowledge can be a learning experience; these social constructivist environments are democratizing information because anyone can, and many do, write for Wikipedia or create their own wiki for private or public devouring. Personally, I've never used Wikipedia, created a wiki or read anyone else's wiki. If I want information, I turn to what I've always thought of as more authoritative sources.
However, I've become convinced of a few ways that Wikipedia can be useful in the classroom. Once a class has completed a unit or research project, they could read Wikipedia submissions on the same topic and evaluate that knowledge based on what they already know. Students could be directed to edit the topics with their knowledge, learning the importance of evaluating credible information. Wikipedia can be used as the initial source of information to get a general feel for a topic and possible ideas or ideas to branch out to before moving further into more traditionally credible academic sources.
Wikis can be used in the classroom by teachers who write their own submissions for students to edit and expand on with information they've learned. Students can create their own wikis as book and movie reviews. Study wikis can be outlined by teachers for students to fill in with information they've learned on a subject. All students can edit and submit what they've learned to create a large study guide from which all students can benefit. A class can collect recipes related to a culture they're studying and create a wiki for private or public viewing. If public, more submissions could be collected from people all over the world, even those within that particular culture. What a socially constructed environment that would be!
Yes, Wikipedia and wikis don't seem to have the extensive verification of knowlege, and citations available for readers to check the knowledge, but they still have a value that cannot be ignored. If teachers brought this tool into the classroom, their digitally-aged students would improve their writing and revision skills simply because of the time spent using this tool, could learn the valuable information literacy skill of evaluation, as well as, become more engaged in their learning. The vision of students fully engaged on the computer as they create, edit, evaluate and write is far more appealing than seeing them slumped in their seats copying notes from the overhead projector.