<< This plugin for Microsoft Office is available to anyone with a Google Account, and brings multi-person collaboration to the Microsoft Word, Excel and PowerPoint applications that you may still need from time to time. The plugin syncs your work through Google’s cloud, so everyone can contribute to the same version of a file at the same time. Learning the benefits of web-powered collaboration will help more people make a faster transition to 100% web collaboration tools. >>

http://googleblog.blogspot.com/2011/02/new-ways-to-experience-better.html

http://www.youtube.com/watch?v=H12teRzulW0