JotSpot
Stephen Downes referred to JotSpot - an applicaiton Wiki in one of his recent newsletters, so I thought I'd check it out.
JotSpot is an online Wiki application that is currently in Beta format. It is easy to sign up for access to the Beta version, and proceed with creating your own online Wiki. I've requested an account, but haven't had time to set one up yet - at least, not to the extent that I can make it available here.
There's a great online editing funtionality - with SOAP and RSS features listed as things that will be included in the future versions.
There's a very good explanation of the product available in the TOUR you can take from the main page. Stephen pointed to Lawrence Lessig's communal rewriting of Codebook as an example of what can be done with this product. Worth a look!