This one came out of nowhere. Chrome OS is now available for download. It's not the final version, but a beta.
2009-10-21: New Chrome OS 0.4.223 beta is available now!
Chrome OS is a brand new free operating system built around the revolutionary Google Chrome browser.
The project aim is to provide a lightweight Linux distribution for the best web browsing experience.
Featured software in Chrome OS: GNOME 2.24 desktop environment Google Chrome 4.0.223 web browser Google Picasa 2.7 photo manager New! OpenOffice.org 3.0 office suite GIMP 2.6 image editor Flash Player 10.0 plugin and much more!
System requirements of Chrome OS: Processor: Intel Pentium, Xeon or newer; AMD Duron, Athlon, Sempron, Opteron or newer RAM: min. 256 MB Hard disk: min. 1 GB Graphics card: supports most modern graphics cards