Just took chromium OS chrome OS for a whirl and its a pretty good os. Downside is that you have to be connected to the internet to do most of the stuff. I am trying it on a compaq presario c700. The boot is quite fast. My main motivation was the fact that I knew that Google had offered an offline version of docs and i wanted to try it out. Offline Google docs seems to be working well for only documents(text not spreadsheet). That's okay considering it is a beta product.
But my main disappointment is that the touch pad does not work well. Clicking via the buttons and tapping the touch pad works, but moving the mouse does not work. I have tried some of the suggestions on the forum but i still haven't been successful. But I think that the mouse would work with the 'lime' build as they call it.I will give it a try and see how it goes. All in all i am amazed at the power of html and java-script.
With more native looking apps coming up and more offline support Google chrome OS can build and integration of web and desktop that we have not experienced before.