www.twiki.com was an interesting site.  It was not an education site but rather a business site.  This is an example of how business communications are evolving and evidence that we need to teach our children now, even if these things are outside of our comfort level, because they WILL be using them in their adult lives.

www.wikidot.com was another site I found to be interesting.  They boast the following points:

• "discuss research topics and collaborate with coworkers,
• publish lesson / lecture notes and materials, including any PDF files or PowerPoint slides,
• inform students about upcoming topics and events, also using RSS feeds to keep them up-to-date,
• publish homework tasks,
• create forums to discuss topics,
• organize whole classes using Wikidot,
• create separate wikis for groups or for each student"

The site also offered interactive modules to have on your wiki, from video and pictures to RSS feeds and del.icio.us bookmarks.  The site is geared towards education and has a free and a professional upgrade option.  I like the amount of space that it allows and also the interactive modules in one place.  Its nice to not have to recreate something every time!