Vicki Davis is one of my favorite bloggers, and I've linked to her coolcatteacher blog many times. She has put together an outstanding presentation on Wikis on the K12 online conference site (including a 27 minute video), and a very cool follow-up activity. I've signed on to participate in the Tagging To Help Teachers Wiki. This will help me to learn more about tagging AND more about Wikis.
In the very near future you'll probably see me using some tags on this blog. Just as soon as I figure out how to do them.