Hmm, I guess that is the sort of pertinent question I should have asked. I was imagining a more global level collaboration on an overall work of fiction rather than a more character delineated type of thing (similar to the play by post RPs Ive seen). Not saying Im not open to the other, though.
On the iGoogle thing, I think you were meaning Google+, the new facebook alternative? iGoogle is a widget based Google homepage service, not unlike Google Desktop. IF you are simply looking for an online service that allows multiple people to collaborate on a single work without having the hassle of passing around revisions, Ive had good luck in the past with both GoogleDocs and Obsidian Portal, the latter being an online collaboration tools geared toward RPG games (DnD and such), and is similar to a rather intuitive sort of wiki, at least how Ive used it before. I highly recommend it.