Here are 7 easy steps to safely test Chromium OS on your netbook using a 3GB+ USB flash drive:
Thanks to Hexxeh for building this image file. You can find instructions for OSX and Linux as well as an FAQ on his website.
You can find a Chromium OS hardware compatibility list here.
Note: You may need to use a wired network connection because many wireless cards are not supported currently. There is a modified version with wifi drivers available for Dell Mini 10v users but it has some quirks and the download is super slow (<20kb/s for a 7.5GB file).