Schtuff.com

This is another Wiki tool (see my Writeboard entry). Schtuff allows more sophisticated editing than Writeboard, and allows you to designate the email address of those who are permitted to view, edit, and/or comment on the Wiki document. You are allowed three Schtuff spaces at no cost, each of which can have multiple documents. The one thing it does not have, that Writeboard does have, is the ability to track changes made to a document over time.