Apologies if this is old news - or if this should have gone in a different forum.
Google is developing a new method of communication they're calling Wave
(article here). This looks very promising to me for project collaboration. Instead of using email with "reply all" when communicating back and forth with project team members, one can start a "wave" which will include everyones replies and discussions.
One nice feature is the ability to insert comments anywhere in the wave. For example, with email, if you want to respond to separate portions of someone's email, you have to snip the text apart. With Wave, you just click inside the text and insert your comment.
You can also insert pictures, which strikes me as a good way to send snips of drawing details to folks for review & comment. (As an AutoCAD user, I really like that).
It'd be great for document collaboration. People can make changes in real time, which are highlighted to show what was done, and tagged to show who made the changes. If you happen to get invited to a wave after some editing has been done, there is a cool little playback feature to show you what has transpired.
There is a demo video
here. It's rather long - I had to watch it a bit at a time while doing something else.
I'm going to be keeping my eye on this one.
Sign up for updates
here.
I think you can even sign up for beta testing. It's going to be open source so that others can develop applications for it.