Something which someone linked to during the week was whiteboardwiki.IIRC from the project’s sourceforge page, some of the backend is written in Java so I’ll going to get the tarball and have a look at it. I’m not sure when he last updated it – I think the change control suggested it might have been a while.
Interestingly though this is something I’d like to see integrated into googleplus. Not sure what the architecture behind it is but I’m also inclined to wonder if this couldn’t be easier to sort out in HTML5 – way to choose a project to rejig those skills – probably easier to write a front end throw away board…more to the point is how you write a savable one and maybe which user would own it if the idea were used across different users.