Yes, you can install Chrome OS in your laptop. I installed Chrome OS in my laptop way back. Chrome OS is just a Linux version with Google Chrome as default browser. Actually it is derived from Open Suse a Debian based operating system. The OS I installed in my laptop is different from the OS that I see in latest laptop. I installed developer version in my laptop and now the Chromebook comes with official Chrome OS. Only difference I found in the new version is its user interface. I searched for new Google Chrome OS but I end with same old version. You can download and install old version by searching Chromium OS. Installation is similar to latest Linux distros. To install the OS, burn the image to a blank disk. Insert the CD to run live Chrome OS. In the live OS desktop you will the installer. Double click and give the password as 'root' to install the OS.
My experience with is OS went bad. I was not able to install video plugins and so I was not able to play videos. It will take extra effort to install any application you want. All you have is Chrome browser and you can use Chrome apps.