Is it possible to turn off camera functions?

I work with my phone in my Levis pocket. My phone is pretty beat up after about three months with scratches everywhere. I have to have a clamshell or flip type phone or the screen would be unreadable.
The switch for the camera is always activated in my pocket and I always have to turn it off when I retrieve the phone to use it. That camera seems to be depleting the battery while it is viewing the blackness of my pocket, somedays I get 10-12 hours before the battery is dead.
I have looked at the menu and I can not find how to turn off the camera function.
I have a Samsung 339, great phone, but I have got to kill that camera.

Anyone have similar experiences or suggestions?