3D Print any skull from thingiverse or any other convenient Halloween prop.
3D Print the Calaca "skull" adapter, this is my original design, you can get it from thingiverse or shapeways.
Attached LEDs to the skull's eyeballs and the servo to the jaw of the skull
Use a piece of pvc pipe or a CD holder to set your skull and put your bits to work.
Gather any halloween props you have around your house to give your skull a little flair.
As far as programming, I use standardfirmata for Arduino and Minin Minin for Processing.
Connect everything, get ready for a Monster Bash and Happy Halloween!