Thing 16 Wikis

Is there more to learn about WIKIs other than Wikipedia? Yes, I've discovered. For quite some time, I've been considering different ways to gather and organize the reference information I've gathered. A Wiki might be the answer.

Mediawiki: http://www.mediawiki.org/wiki/MediaWiki - the software originally written for Wikipedia
GoogleDocs
Wetpaint: http://www.wetpaint.com/
PBWorks

Would a wiki be a good option for branch or system projects which require documentation and collaboration?

Wiki about use of wikis in libraries:  LibraryWikis 
LibraryWikis categorizes its contents by intended users:
-collaboration between staff
-collaboration between staff and patrons
etc.
http://seriesbinder.lishost.org/index.php/Main_Page is an example of a wiki built to give access to children's and teen literature in series (chronological lists)