Using a motor, some LEDs, a battery, and a few other things, it is possible to create an amazing device that serves no purpose aside from decoration and learning. LEDs on a small disc will light sequentially as a motor spins. This is a fine alternative, if I might say, if you do not wish to go through the process of buying/building, and programming a microcontroller.
Step 1: Parts
K'nex (can be substituted with any other structure-building thing)
Wire (Hookup, and stranded wire)
Cardboard, Plastic, or similar
Aluminum Foil (Conductive ink of some kind is a preferable substitute. I didn't have any.)
Wood or something to form a base