My first experience with wiki was a few years ago when I set up a TikiWiki as a tool for long-distance collaborative program planning in my work.
This worked fairly well and I continued to sample different wiki platforms. I recently became a fan of Plone as a Content Management System, using ZWiki as one component of it. My current (2005) project is the development of the Rootstalk Project, an online grassroots political think tank (http://www.rootstalk.org).
I've read much on this site about the attempts to use wiki for political discussion and the subsequent problems and failures. Some folks say it is a tool that simply can't be used for political collaborations. I'm either an optimist or a fool for trying, but I'll give it my best shot.