浪費一個按鍵? Don't you know that with AE Button plus, you can assign **Any button** to emulate 4 different actions (1/2/3 press and hold)? Beside the power, camera button (and the physical keyboard), X1 got 13 physical buttons (52 actions) which should be more than enough for any need.
710382, it will not be built-in. But 3rd party apps like CE-Star will provide that.
My SE X1 rom-> http://forum.xda-developers.com/forumdisplay.php?f=471