I use wikis for several things. I have a section that I use for students to use as a refection tool since we are not allowed to have blogs. I have another section that I use to post student work/projects such as powerpoints, movies, glogsters, etc. In a third section I have an area for chapter summaries, notes(from slideshare.net) and practice quizzes (from mystudiyo.com) Finally I have another area where students post pictures, voicethreads, blabbersizes, toondoo comics and/or animotos describing lab activities that we do in class.
We also created wikis to use with teachers. There is one that is for our teachers union to help us communicate events, updates, meetings, etc. The other one is used as a contact log for parents and a tracking system for students that are not doing well in class. We don't have a common time to meet with teachers that we share students with. Using a private wiki has been very helpful to identify students that are struggling and documenting interventions, conferences and parental notification.
Can you give a link to your wiki? I'm a HS chemistry teacher and am looking for wiki ideas that I can use in my class. I also know someone who writes for the The Science Teacher (National Science Teacher Association) who is looking for examples of classroom wikis to use as examples in a future column.
The wiki I use with my students is set to private. I sent you a twitter DM regarding that site. I also started a wiki http://sciencecafe.wikispaces.com based on a discussion thread from the NSTA listserv that is public. It is a collaborative site for science teachers to develop units based on a cafe concept from Margie Gifford. I am also developing a wiki for a grad class that I teach on using PowerPoint interactively with students at http://iu18ppt.wikispaces.com/ Hope this helps you form ideas for your classes. Wikis are really a great tool that can be used in many ways.
My first attempt at a student-built wiki was a field guide to local insect species. The students were to follow up the summer insect collection with creating a wiki page for one insect. I was neither overjoyed or dismayed with the results. I did learn quite a bit about my students and their very varied digital-literacy skills. http://phsinsects.wikispaces.com/
My first use of a wiki site was an attempt to create a physiology textbook at Wikibooks (sister site to Wikipedia): http://en.wikibooks.org/wiki/Human_physiology and I was happy overall with it though it was fairly difficult for students to learn to use it (beginning college students).
I then started using Wetpaint (which, at the time, allowed educators to get ad-free sites for free). My most successful venture there was the Anatowiki: http://anatowiki.wetpaint.com.
Currently I am at a new job where I am getting some serious pressure to not do these sorts of online ventures, so I am laying off it for a time. Too bad, really since the anatowiki could be made more useful with a bit more organization and editing.
I am experimenting with a wiki during the last quarter to give my students an opportunity to write their own textbook. They have been told that next year's students will be using the site. So far, they are really excited about posting articles. Now I have to organize the students and give them guidance on the merging & editing process.
I had the kids track their science fair projects on in a Wiki page that spawned off our class page. It made it easy for them to access from home or school and I could make comments late at night when I finally had a chance to sit down and think for a moment. It made copying and pasting their info and sources together much easier so they could remember where everything came from.