Arduino control software for GE G-35 LED christmas lights.
THIS CODE IS UGLY AND UNSUPPORTED :) I think the cooperative multitasking is a nice hack, though, and the HTTP server is a nice mechanism for controlling your Christmas light programs ;)
My current setup is two strings of G-35 lights (a 25-bulb and a 50-bulb), driven from an Arduino Mega 2560 with a WiFi shield.
The lights in action: http://youtu.be/jvRrTi9ftyA
Good technical overview for hacking the G-35 lights: http://www.deepdarc.com/2010/11/27/hacking-christmas-lights/