At first I thought of doing the slit for a site gauge type idea. This would still provide alot of protection, but would cause a stress point that could still be broken. Opaque would be nice to solve the light problem, but I don't like the idea of not being able to see inside at all. When someone mentioned clear I did a quick search and plasti-dip does indeed make a clear rubber coating that is recommended for glass and it comes in the spray version! I'm going to Lowe's this weekend to pick up a can of the clear since I think that will be best. For anyone intersted in purchasing online, check this out.
I will spray a couple of beer bottles and bust them to see how the glass reacts. My thoughts are it will be harder to break the glass and when it does it will hold like laminated glass on a car windshield. I will report back with pics once my experiment is rolling. Ya'll keep the ideas rolling too, this is really exciting.