To explain my 4x4x4 interactive LED-cube published before, a bit more clear, I will try to make my first step by step instructable.
This 4x4x4 cube is interactive by using the top four corner LEDs both as LEDs and as sensors that will react on light. Depending on what LED gets the least light, the cube will run a different show.
Step 1: you will need:
piece of wood
computer with Arduino software
4 resistors that go with the LED's (yes just 4)
some small COAX wire (isolated wire)