Making a bootable Chomium OS memory stick is very simple.
Once you have downloaded IMG WRITER and and a Chromium OS from the downloads section of this site, you're ready to begin.
First thing to do is to install IMG WRITER.
Once that has been done you need to open IMG WRITER and select your USB from the drop down menu at the top right of the window.
You then need to select your IMG file:
If you have downloaded the Chromium IMG supplied by hexxeh, you will need to extract the IMG from the folder using WINRAR. For instrcutions on how to use winrar please visit this TUTORIAL. (The files mentioned vary but the principle is the same.)
If you have downlaoded the Chromium OS image supplied by myself on MEGA then you DO NOT need to extract the IMG.
You then need to select the IMG file from where you extracted it to or downloaded it to.
Once this has been done, click WRITE at the bottom of the window.
You will receive a message giving you a WRITE TO PHYSICAL DISK message, Click okay.
Once you receive the completed message, you are free to restart your computer and boot from the USB.
For instructions on how to boot from a USB drive, either use google or contact your computer/motherboard manufacturer as this varies per computer.