Wiki! Wikis! My first experience using (and by using, I mean actually contributing) a wiki was during grad school. It was my records management class, and one of our wiki assignments was to be a "definition taker" for a certain class period and we had to find definitions to the various words we discussed during class. I always lived in fear that I would get some tragically hard word and end up looking stupid. Though, goodness knows, I don't need help for that! Now that wiki was password controlled, so only members of the class were able to access it. What was especially nice with it, was that at the end of the class, we were left with a permanent spot on the web of everything that we learned over the course of the semester that we could go to for reference.
My second use was an on the job experience at Wheelock college where the reference librarians had their own wiki (as did the circ staff). This kept all of the reference librarians up-do-date with various questions asked, questions that were still being worked on, and things that we could do when there was nothing else to do. Once tasks were complete, we could cross them off the list so others would know that they could move onto the next task. The wiki also included useful guides for things such as filling ILL requests.
Wikis can pretty much include whatever the users want, on a variety of topics. They could be used within libraries for librarians to share useful links for reference sites/article discussion/reviews/etc.
Does this sound like a good textbook answer?