I talked myself into buying a couple launchpads when I saw them announced on Hackaday, though I have very little idea what I might do with them. My first thought was to update a nifty lil robot that a friend and I made a few years back, using a Parallax product with very little power. We could barely make it follow walls and avoid objects, but that may have been simple lack of experience.
I've had a few random ideas since then, from a desk-pet toy to driving a mini CNC I haven't built yet. (Been breaking down junk to get some nice rods and linear bearings, got a couple steppers but n