Download PocketGuitar and you’ll be able to rock a virtual guitar or bass on your iPhone or iPod Touch. Get a friend to load up the BeatPhone drum sequencer and you can get the virtual band back together.
You’ve got to appreciate the $400 mp3 consumer being converted into a music creation device.
I was peeking at the source tree for PocketGuitar and the sample data is composed of normal WAV files, one for each string. You can simply replace these with your own note recordings to give your iPhone its own unique effects.