We've seen mods for Guitar Hero in the past, but this is the first I've spotted for the DS version. Eric Ruckman, unhappy with the gameplay of Guitar Hero: On Tour decided that, instead of cutting his loses, he'd mod a PS2 Guitar Hero controller to play the game.
As you can see above, that includes a special housing for the DS itself (it's still used for strumming), and even a built-in FM transmitter with its own screen, which lets him pump the audio through his home sound system.
Sweet modding skills Eric, but as the old saying goes, "just because you can, you probably shouldn't have."
Hit the jump to see a video demonstration of the mod in action.