This video again is excellent and well worth watching. It gives a quick concise introduction to Wiki's.
Personally I am using pbwiki.
This video it but one in a serious of videos about "web 2.0" applications all "in plain (united states) English. The visual aspect of teaching is well done. There are further videos about Twitter, social networking, blogging, RSS, pods etc. You can search the related videos by viewing the other video posts by Le Le Fever.
With best wishes, Heli.
Wikis in Plain English