Indistinguishable from magic
Since the latest update (2.1), my iPod’s haptic interface has gotten even better. I rarely trigger a button by brushing against it accidently, and the wheel subjectively “moves” more naturally. It even works reliably through leather gloves, but is not fooled by them when not worn.
I believe this particular technology has http://catb.org/~esr/writings/magic-cauldron/magic-cauldron-1.html. How do you improve on an interface like this? I suppose the next generation will have to http://www.ibva.com/ via the headphones.