Zoho has come up with a new product - a wiki : http://www.zohowiki.com/
I have been watching and using the products of Zoho very frequently. It is interesting to note the speed at which they are adding new products to a already rich suite of products. Most of their domains of work intersect with google. They have a online word processor, spreadsheet, now wiki, a presentation tool, form creator and many more. The plug-ins they have make their use easy and seemless.
Here is a page to showcase the power of their wiki: http://raju.wiki.zoho.com/Zoho-Wiki-Page.html
Good thing is you can import data from their word or spreadsheet. This data will remain synced with the original file. So, you just need to change the original file to get it reflected at an appropriate place. This is something I always wanted. It also looks to be more powerful than jot in respect that to you can give permissions to edit at some selected locations in the whole file.