Lock while on a call

Is there a way to lock the phone while on a call with bluetooth headset? I keep hanging up on people when i put my phone in my pocket and am talking on bluetooth.

I also have issues with the proximity sensor. I am searching for ANY way to lock to screen while on a call...

Ideally, I would like to find (or write even if i comes to it) a program that would completely shut the screen off when on a call, with possibility to unlock by using one of the physical keys on the side, the camera or voice control key perhaps.

Is there anything within Android preventing this type of app from being written, or has it just not been done yet.

I know I am not the only one with proximity sensor issues. Out of 5 friends who used my phone to talk on it normally, 3 of them managed to either mute or put speakerphone with their face while on the call.

Again, if anyone can recomend a program to do this, I would be very grateful.

Or, if anyone smarter than me is reading this, I would help with development any way I could and would be willing to pay about $10 for the app if it made its way to the market.

I am no pro. there is a sensor on the top that turns the screen dark,  nota blue tooth fan yet.

So would that be bypassed?

butwhy not  if allowerd. scroll up your dial pad, it locks your phones keypad or more ,and needs a double touch?

have you tried that?

there's an app called lockbot free its ok but it could use improvements