Originally Posted by Hanwei
Actually, the mute button will toggle your sound profiles between Vibrate, and whatever profile you have currently set to active.
So if your Storm is currently in Silent, holding the mute button down will toggle between Vibrate and Silent.
And it only works if the phone is locked (I don't have a case so I can't comment if it works then or not).
Also to the OP if you get TalkLock it will stop your face from hitting the mute button while on a call.