Click on your OS for instructions: (this is for Linux) No need for unetbootin. Be careful using dd command also. Drive letters are very important.
Extract the IMG file from the downloaded archive.
At the shell, run the following (where sdX is your USB stick and ChromeOS-Lime.img is the path to the IMG file you extracted): dd if=ChromeOS-Lime.img of=/dev/sdX bs=4M
Boot from the newly created Chromium OS USB stick!
Basically. extract image from zip in Xandos file manager. Open terminal while in Xandros file manager where zip and extracted iso sits. Then become root in terminal of Xandros (sudo?).
Use fidk -l command in another terminal to get /dev/sdx locations of drives like usb stick for the
Warning. If you screw up /dev/sdx location. You may overwrite xandros install on internal drive.