We're using PBwiki as the wiki platform for this site.  It's a freely hosted site with easy-to-use editing features and good site protection. We've set this up as a private site to which we can invite users.

Graphic explaining PBwiki features:  http://pbwiki.com/features.wiki

How to set-up a PBwiki in 30 seconds: http://pbwiki.com/education.wiki

PBwiki user community online help forum: http://getsatisfaction.com/pbwiki

Why use PBwiki: http://pbwiki.com/pdfs/business/business-whypbwiki.pdf

White paper on how to use wikis for collaboration: http://pbwiki.com/f/PBwikiCollaboration.pdf

Why I use a wiki?

• You want to increase student engagement using a safe online wiki
• You're tired of complicated solutions that nobody uses
• You want a no-hassle way to showcase your students' work online
• You want a central place for your group to collaborate
• You want one place to put your files and thoughts so you can access them anywhere
• You want a partner to share best practices on collaboration

Why use a wiki instead of a blog or forum? 

Blogs are great for one-to-many communication, such as one person writing about personal finance.

Forums are good for letting many users ask questions and letting many people answer.

Wikis are excellent for collaboration. If you want to let students collaborate, add files, suggest links, and create a document that's comprehensive and up-to-date, use a wiki.

Case study of PBwiki being used by university institute: http://pbwiki.com/content/casestudy-ivi