Any app to lock touch screen while another app is running?

[New Daddy]

I'm looking for an app that will lock the touch screen so there won't be accidental touches (whether by a finger or the butt), while another app is running.

My plan is to run Google Maps for Mobile while skiing but keep the mobile set in the pocket. I want to keep the power on the whole time so I can locate my position immediately upon taking out the mobile set from the pocket. But I want the phone to be running Google Maps, instead of showing the lock screen, so I won't have to take off my gloves in the cold weather to unlock the phone. By necessity, I need an app that will "lock" the touch screen so no accidental touches will be made to Google Maps while the phone stays in my pocket.

Is this feasible?