I built this back in December of 2013 for a project. This is a ring light for the GOPRO Hero 3 build with hardware from Adafruit, and these STL's.
Make sure the print the light cap with a clear/transparent filament, and the light housing with a black/dark filament.
The LED ring is populated with NeoPixels, so they will need to be run with a micro controller (I picked up a Trinket from Adafruit, and a lipo too.) If you don't know how to program an arduino this is a great time to learn.

Parts
http://www.adafruit.com/product/1463
http://www.adafruit.com/products/1905
http://www.adafruit.com/product/1501

Code bits and Trinket programming for the neopixel
https://learn.adafruit.com/kaleidoscope-eyes-neopixel-led-goggles-trinket-gemma/overview