We have covered plenty of awesome kinetic sculptures here in the past. Not everyone fits on a desk though. The Asterism does. It is a hypotnic pendulum toy powered by an electromagnet that gives the illusion of perpetual motion. The pendulum swings back and forth while the three asterisms spin and move through the air. At the very least, you will find yourself staring at it for a while instead of working.
The main pendulum measures 11.5″H x 8″W while the base measures 4″W x 1.5″H. You will need a 9V battery to get this to work. Makes a nice gift for the geek in your life.