collaboration tools

Wikis: What are they? Why are they useful?

Wikis are all the rage. What are they? Why are people so excited about them? How can I start one? Why would I want to? Read a basic description of wikis here:http://en.wikipedia.org/wiki/Wiki When you're done there, you can find a lot more information at the oh-so-helpful site, Howstuffworks.com: http://computer.howstuffworks.com/wiki.htm.