This guy created a music app and installed it on multiple Android and WinMo phones, and even an iPod Touch. Then taped them together to make a bizarre looking guitar, on which he can play Cracklin’ Rose.
It wasn’t easy. He ended up writing it three times: in java for android, in C# for windows mobile and in Objective-C for iPhone. To play them all at once, he just taped them on a piece of wood together with a battery powered speaker, then added lots of audio cables.