Also, I was lucky enough to receive a Gameboy Advance SP for my Bananniversary present, along with a Nanoloop cartridge! That means I can make sweet drum beats with the sounds of a gameboy. I am also working on getting a Little Sound DJ cartridge for classic gameboy. My goal is to figure out how to sync up a classic grey gameboy with my gameboy advance, and then run GB Advance with nanoloop, and greyboy with LSDJ, and then maybe sync them with my drum machine somehow. And I want to custom paint both gameboys. Because that would be cool. And noisy. With all the noise.
Here is an example of a Gameboy with LSDJ making some music.
*edit 11.28.09 - This video and music was made by a person who goes by the name "assgroos" on YouTube.