I recently picked up Developing Games in Java by David Brackeen and have been reading through the first couple of chapters.

Using the copius code distributed with the book, a couple of hours in photoshop and a little creative alterations of my own.... I managed to create a demo animation of a RoboRally conveyor belt that turns on and off with the space bar. :) It's lame, but it works. I'm calling it a night.