The UW Colleges uses Google Apps to provide a wiki environment. We utilize the Google SItes tool, which can be a wiki, but has other features as well. Instructors aer using this tool to have students work in groups to create a project, write a document, etc.  Wikis can be requested for courses when requesting Desire2Learn coruse sites. This video is a thorough introduction to the Google Sites wiki.  Be sure to use Firefox or IE to view this video. Originally recorded 8/23/2011.

Check out this document on Wiki site managment: Google Site Basics

More information abouto Google Sites (Wikis) can be found at on the Google Sites webpage.