RingerSwitchTool Tweak – Use Your iPhone/iPad’s Mute Switch As Orientation LockMonsta'd on February 16th, 2012
RingerSwitchTool is a neat little iPhone/iPad tweak in Cydia that lets you use your device's (physical) volume mute toggle as a screen orientation toggle instead.
Once you download RingerSwitchTool, just head into your main Settings.app where you can choose whether your volume switch controls the device's volume or the screen orientation lock.
RingerSwitchTool is available for free in Cydia. There are no new icons added to your SpringBoard with this tweak.