Just stumbled across this great 182 page doc on the communicator.adm file that you can use to control the Microsoft Office Communicator.
Now if you have looked at the communicator.adm template and are wondering how you could fill 182 pages discussing it, the answer is of course, Picures! This doc includes lots of screenshots and shows you what the user will be seeing within communicator, so is definitely worth checking out if you manage Office Communicator as part of your OCS deployments.
Download details: Office Communicator 2007 R2 Group Policy Field Guide
Microsoft Office Communicator 2007 R2 Group Policy Field Guide