[Air-L] wiki tool suggestions?

Hi all, I'm looking for suggestions for wiki software to use with a class. I don't want to have to install anything, and am of course looking for something simple to set up and use. When this question was asked some time ago, the following sites were suggested: http://www.mediawiki.org http://phpwiki.sourceforge.net/ http://moodle.org/ http://pbwiki.com/ http://www.seedwiki.com http://www.pmwiki.org/ What would you recommend now? Thanks, Catherine Middleton