There is a great collection of links to wikis to explore here. I could spend hours and will probably go back and do so. I particularly like the SJCPL Subject Guides, using a wiki to collect pathfinders. I can do this. This set my mind whirling with ideas on how to develop a wiki for my pathfinders.
I also really liked exploring the Blogging Libraries Wiki and spent a lot of time on the school libraries list, exploring how other school libraries are using blogs and wikis. It was great to have del.icio.us to tag the interesting ones to come back to. I also found a count down clock to the latest Harry Potter book on one site, but after exploring it, I decided not to download it. You can find it at Scholastic online if you are so inclined. I am going to be messing around with this "wiki thing" for a long time.
Finally, I came upon this video again, and I am going to use it with the teachers at school. These guys do a great job.
Wikis in Plain English