I have wanted Ambilight for my TV for a while, but I don't want to use the specific TV etc.
Found the Arduino based clone, realised I had all the stuff to do it lying around, and so I've started.
Take a 32" TV, and 2.5m worth of individually addressable RGB LEDs and what do you get? Ambilight!
Currently:
336 LEDs; 60 on the vertical and 108 on the horizontal.
Arduino Uno.
Lightpack Prismatik and Ambibox control software. Limited to 255 and 300 LEDs respectively, and neither run well on the 10YO laptop I have currently controlling it...
The Neopixel examples script runs fine and looks excellent.