Whatever you do, don't use the tooth method.
You head back to camp after a good, long day of gettin’ after it and pull an icy cold beer from the cooler to celebrate. Suddenly, and not without a small measure of panic, you realize you forgot your bottle opener. Before you resort to breaking the neck off your Polygamy Porter with a rock and risk drinking down busted glass with your brew, open your eyes and look for some other alternatives. There are plenty of items in camp that will help you get access to a cold one. Depending on your chosen activity, you may have nearly limitless options.