Over in this response, I discussed the possibility of people collaborating in pairs on the Rear Window project. Reply here if you have any ideas about what it would take to be able to successfully collaborate with someone, and if you would be interested in collaborating with another A:M user on a Rear Window short. (That would not prevent you from doing one separately if you so desired.)
Remember that there are some collaboration tools like Skype for video chat and desktop sharing, SVN and GIT and Mercurial for sharing revisions. You could also share a WIP forum post to coordinate. Are there any other tools that would help?