We have been using wikis in our business as well as promoting the collaboration tool to our clients.  The Dallas Mavericks are experimenting with a public wiki for use by fans.  The Dallas Observer talked to Mark Cuban about the wiki,

But, then, that is the point. Team owner Mark Cuban tells Unfair Park that MavsWiki is intended “a way for fans to have more fun and connect closer to the Mavs” by posting their fond memories of games way past and recently present. Mavs staffers (meaning, interns) will augment the site with old game stories from the Associated Press and other media outlets. Cuban also says, “I think it’s a first of any kind”; certainly, no other pro sports team has a similar site…at the moment. 

Check it out here: Mavswiki.com.  The cost of deployment is very low compared with traditional fan sites, and it gives your brand a great opportunity to let your fans generate content.  It will be interesting to see if dedicated wikis (versus public wikis like Wikipedia) take off.  What do you think?