Here's some feedback : tapping the spacebar with the phone? That's dumb. Why? I have to hit hard for the "bump" to happen. But that's not really a problem since hitting a keyboard with a cellphone makes no sense. Consider another scenario :
a) The user clicks somewhere (or vocal command?) to enter a listening state.
a) The user clicks somewhere (or vocal command?) to enter a listening state.
b) Then he shakes his phone.