Has anyone suggested DimDim? http://www.dimdim.com
It's free for up to 20 people, available for Windows, Linux and Mac.
I have installed both Chrome and Chromium on about 15 machines and 3 flavors of Linux. In each case the UI responsiveness is amazing. Huge improvement over Firefox. So far everything has worked beautifully on each of these machines. No problems with Flash. I'm surprised that the link review complained about the lack of extensions. There are plenty of extensions. Kinda made the rest of the review look poorly researched.