Using the Knowledge Garden as a good and bad learning experience has made me think of ways to use wikis in my classroom.
One idea I used recently was to get Group A students to research a topic and create a wiki page. Group B students then read the page and asked some questions and made comments on the page.
Rather than the facilitator generating the questions and calling for comments, the collaborators did.
Students often have to do research of their own to come up with the questions and comments. Group B (C and D) students were also busy creating pages in the same wiki and going through the same process.
I find it takes a lot more scaffolding at first, and probably has different learning outcomes to my own experience, but the students are motivated by the technology. Its a great way to teach collaboration, critical thinking skills, reading and writing for understanding, etc...