MK802 $74 Mini PC running Ubuntu Linux

The MK802 is a tiny PC with an Allwinner A10 CPU, 512MB of RAM, 4GB of storage, a mini HDMI port, mini USB port, and full-sized USB port. It also has a microSDHC card slot -- and this video shows that while the device ships with Android 4.0 you can load an alternate operating system on a memory card and boot from it. This is a pre-compiled Ubuntu Linux image.