I managed to build an Image from the Chromium OS source code and I have to say that it was very easy to build and Google themselves provided clear and simple build instructions.
Here are some of the screenshots of Chromium OS running in VirtualBox on Ubuntu Karmic
And here are some useful links if you are interested in building the Chromium OS from source:
Source Code
Getting and building the Chromium OS source code
Browsing it
Navigating it



I have tried using Chrome OS in one of my desktop PC’s, the overall performance is above average to excellent .