MobileWhack reports a cool example of multi-touch for small-scale devices such as the iPod Touch: the Pocket Guitar by Shinya Kasatani. You can even play along with the music on your iPod. It is an initial release and future updates promise configurable “plucking” sensitivity so you can play a string by dragging your finger over it in stead of when touching it.

It is great to see what kinds of flexible User Interfaces people can come up with when the one-finger restriction is lifted. Imagine what the experience with this application would be when combined by a tactile feedback mechanism (i.e. feeling a small vibration when you play a string). What is less obvious is that it actually uses multi-touch to a greater extent than iPhone and iPod Touch does, because the standard Apple software mostly uses one-finger gestures. Two-finger usage is pretty much only required when scaling and rotating an image and potentially when typing on the on-screen keyboard (for shift-keys and such; they seem to be using a single-touch keyboard!).

The sourcecode for the application and release information can be found at http://code.google.com/p/pocketguitar/