Garrett Mace, aka Macetech, built this LED NYE ball, using his own Macetech LED controller and Arduino shield kits (and a Seeduino). He writes:

I used six Satellite Modules (high power RGB LED arrays), six ShiftBars (three channel LED controllers), a Seeeduino, and a ShiftBrite Shield to build a New Year’s ball for our own mini Times Square event. The ball was a “sparkleball” made of about 120 16oz plastic cups hot-glued together. We threw a rope over a branch and lowered it at midnight…it lit up the whole yard!

2010 New Year’s ball