I bought a little stepper motor and H-bridge. The plan eventually is to integrate it into a steampunk costume, but today I was just getting it wired up to try it out.
I wired things up according to the 4-wire diagram for a bipolar stepper motor from the excellent instructions here.
Here it is running backward and forward off a 9V battery, with the wax off a bottle of whisky on top!
The code is on github, as ever.