[Jay Collett] was having trouble seeing his keyboard when the room was dim. But throwing a light under the desk just didn’t seem cool enough. Instead he built an RGB light board that is controlled by his desktop. The board is based around an ATmega328 with the Arduino booloader. He etched a single-sided PCB to connect it to a group of five RGB LEDs, with a programming header for an FTDI cable. The board communicates with a PC via serial connection, with a C# control application that [Jay] coded to control the color. We’ve embedded a couple of videos after the break but check his page for a package of code and hi-res pictures.
If you want something cool that’s a little bit less work to build check out the EL-wire keyboard from this links post.