I have three assignments I do with my AP Language students using wikis. They do a History of American Literature web page, which is just a glorified annotated bibliography of web source information on the authors we study. Emperor Notes, which are student authored "Cliff Notes" that they work on in groups to produce. I give them an outline to follow through the project to keep them somewhat focused, but when done they have a 30-40 page booklet that they have written in their groups (they usually have a number of weeks to work on this). The third thing is I have the AP students work in groups to create a glossary of rhetorical terms. That's what I do.
