Imagio proximity sensor?

[mdgmcse]

If you want, you can try changescreen:

http://forum.xda-developers.com/showthread.php?t=468488

I use it not just to rotate my display, but it has an option to "Suspend device on face down" "only if NO light", and to "suspend device in pocket".

Basically, I just turn my phone face down and it locks and more importantly, turns the screen off. I can also turn it upside down to get the same result, I guess as if I am sticking it in my pocket.

You can also take advantage of the landscape stuff, or just turn it off if you want to only use the lock screen function, but I had the same concerns as you, and this was a great solution for me.

- Mike G.