Do you know about RaspberryPi? It's a $35 computer that runs a stripped down version of Linux called Fedora ARM. Basically, it is the guts of a smartphone. It has two USB ports, HD video out. You supply the keyboard, mouse, and monitor. It is for teaching kids to program, experiment and invent new computing technologies. Check it out at www.raspberrypi.org
Minecraft is a popular sandbox open world-building game. A free version of Minecraft is available for the Raspberry Pi; it also comes with a programming interface. This means you can write commands and scripts in Python code to build things in the game automatically. It's a great way to learn Python!