I enjoyed the 16th thing. I am pretty familiar with the creation and use of wikis but I never really thought about how useful they can be in the library environment. I really like the idea about using a wiki in the catalog, I think people would love to be able to review books like that, and I know that I always find the Amazon.com reviews of some use.
I can see a wiki being successful in my department as well. Often times we find ourselves doing new and unfamiliar tasks and trying to figure out the most efficient way of completing the tasks. With a wiki then people could post ways they discovered to quickly complete the task.