ColorNode » DigitalMisery.com.

ColorNode is a wireless Arduino-compatible microcontroller board designed to replace the stock controller board on GE Color Effects light strings.

ColorNode was inspired by the original controller protocol reverse-engineering effort featured here:  Hacking Christmas Lights. That work enabled simple control of each individual bulb of these light strings using just one pin on a microcontroller.  The stock controller works nice and the patterns are good, however being able to have full control of the color and brightness of each bulb unlocks the potential for awesome holiday light displays.  Hacking these lights is also relatively inexpensive, compared to using other addressable strings or light sequencers on the market.

Christmas is the season for LED hacking, with some OSHW LED string controllers!