Svegetto at XDA-Developers has discovered a cool feature on the T-Mobile version of the HTC HD2. If you’re in a call while using a Bluetooth headset or speakerphone mode and you want to turn off the screen so you can put the device in your pocket or simply save power, all you have to do is touch the call screen with two fingers. Shaking the device brings the screen back on.

This does not work on the stock European HTC HD2 ROMs, by the way.