I have a Blackberry which I use for work and I've had my HTC Touch HD for a couple of weeks. One of the things I really like about the Blackberry is the way the screen turns off when you slide it into the pouch and the way it comes back on when you slide it out. It strikes me that it would be great if the HD could mimic that - a lot less fiddling around when you are using it on the move. I guess that the Blackberry uses some kind of light sensor to achieve this. Has anyone come across an app that would do the same thing for HD?