The only, yes the only, thing I miss from my old blackberry was the dedicated mute button. Being able to keep the phone to my ear and yet mute or unmute my microphone made conference calls much easier. Today I have to pull the phone away from my ear, then let the screen proximity sensor turn on the screen so I can toggle the software mute button.
What would be awesome would be a haptic mute button or accelerometer mute button. I would like to tap on the back of my phone, while it is on my ear, twice to toggle the mute feature. It would have to have a little mute on, mute off noise to let me know when the mute is on or off.
I was thinking because of the republic wireless hybrid calling that the phone app could be further enhanced by republic for this feature.