Here is an important note before you start. None of this is officially supported. So, you will have to be careful and know what you are doing. Here is a little background on how he started out to do this.
As part of my job, I often want to be able to demo Chrome OS to clients so that they can see how simple it is or to show them a concept such as enterprise enrollment. However, since Chromebooks aren’t compatible with common screen-sharing applications like GoToMeeting.com or WebEx, it’s not possible. Google+ Hangouts do work on Chrome OS but you have to have a user logged into the Chromebook, no demoing the login screen or enrollment process.
So I set out to find a way to run Chrome OS (the official code) on a virtual machine. Even before Chromebook hardware was available, Chromium OS, the open source base for Chrome OS has been able to run on virtual machines (see Hexxeh’s nice nightly builds) but I didn’t want to deal with the rabbit trail of Chromium OS vs. Chrome OS when presenting to clients, I wanted them to see exactly what they’d see on a Chromebook. So with a little scripting, I’ve managed to get Chrome OS running on VMWare workstation
Read complete instructions at Chromebooks and Chrome OS