I love the idea of the arm band controller. With it I could customize gestures to do useful things like unlock my phone without picking it up and then engaging with it via voice. All completely hands free, even though I'm using my hands.
It would be even cooler if you invoke a hand gestured macro that would tell the phone to speak to me the weather, remind me of my appointments and step through my email. I could even do this in public if I had headphones on, and no one would know what I was up to. All with my phone in my pocket.