6955 is a great gameboy-hacker who is using a gameboy to do music. Of course it's very common lately but I like the way he does it: he combines gameboy with pedal effects which is amazing:

I started this project as a street–side busking thing in Toronto back in ’98. 99.9% of street musicians are irritating Bob Dylans. I wanted to do something a little more interesting. Gameboys are battery powered. So are pedal effects. I found a battery powered amp at a salvation army, threw all my gear in a suitcase and hit the streets. My setup has evolved into a solid, self–contained box housing a ton of effects, an amp and speakers. And it all runs on 12volts.

The sole sound maker is a Gameboy running the Gameboy Camera—it has a lo–fi music sequencer–type thing reminiscent of a TB–303 interface. I run the output of the Gameboy through a bunch of effects: filters, distortions, tremolos, delays, pitch shifters. Most of the stuff I built myself using schematics off the web. I try to modify everything… get more range on filters, more distortion, extra controls. I stumble across a lot of mods while debugging the stuff I build. For recording, I use the same gear, and record on a 4–track. I do every song in one take—I do all the effects in real time. No post–production. No computer tricks (...) there are people making Gameboy music, but I’d have to say that I sound far different than most of the Gameboy music. It’s a lot noisier, more rock. Gameboy rock.