Finally A Wiki that I like

I have been trying to find a wiki--any kind of wiki outside of Wikipedia--that serves its users well. I particularly would like to see a class wiki, but I haven't seen many that I liked or that the purpose was obvious. A lot of my friends use Moodle, which is not really a wiki or a blog, but rather a more combined approach. But most who use them have them password protected (for good reasons) since their kids openly post and comment, or edit the site in its wiki sense. (I feel like I'm speaking a foreign language.) Here is a wiki that truly makes me "get it." It gives me something to show at SLI to ensure the principals or other administrators who haven't quite grasped Web 2.0 what it is, what it's capable of, and what its potential is. Check out his wiki from Princeton Public Library.