The boys from MaceTech cooked up an impressive yard display with eight RGB LED modules in eight different pumpkins around the yard. Garrett explains:

We made a control board for eight pumpkins, using eight ShiftBars, 50mm cables, a Seeeduino, a ShiftBrite Shield, and a 12V power supply. The ShiftBar potentiometers were adjusted to deliver about 100mA to each of the 24 LED channels. We wired the LED array boards to the control board using cheap 4-wire telephone station cable from Home Depot.

Read more about it here.