It was only a matter of time until someone decided to put an OS on the Motorola Xoom that wasn't Android. Crafty geek Thomas Sohmers has ported Ubuntu over to the Motorola tablet and has even been kind enough to provide instructions on how to do it. While the actual Ubuntu OS is running in a sort of virtual machine, I don't expect it to be very long until someone completely replaces the Android OS with a full desktop one (like Windows, OSX, or Ubuntu).