The source code and Eagle files are available from my local download or from

Creating a bending/soldering jig.

My first prototype. The cube was build on a prototype board (371 holes) from RadioShack. I used a 12 pin ribbon cable to connect it to my Boarduino.

After I finished a working prototype I created an Arduino shield.

27 LEDs generic (I used 3 different kinds - 9 of yellow, orange, and red - all have a voltage drop around 2.0V)
9 Resistor value depends on LEDs (I used 330Ω orangeorangebrowngold)
1 PCB Order from BatchPCB for $16 (board and schematic)

Here is the Arduino source code for the shield (check out the download section):

I wrote a pretty minimalistic editor in Processing. Just download from the download section and unpack it in the Sketch directory.