To add to what jeremyaarts said, last year Lego released an upgraded version of their Mindstorms set called EV3. I know there was a board that allowed you to en

To add to what jeremyaarts said, last year Lego released an upgraded version of their Mindstorms set called EV3. I know there was a board that allowed you to enhance the older NXT Mindstorms set with an Arduino, though I'm not sure if this board is compatible with the EV3. One of the nice things about the EV3 is that it runs it's own version of linux, however you can also can run a custom version of linux on the EV3 if you want, opening the system up to a world of fun :-)