Glass! Unless it is a BMC which doesn't matter, either way you lose there, LOL. I will say like others that outside I don't really enjoy my real beer as much, due to the skunk-factor of drinking out of glass, unless I'm out of the direct sun. I'm a huge outside drinker though, love those patios with umbrellas.
You guys... you need to get Corona bottles to pee in! Top them up with some carbonated water, cap them, and leave them in the garage for beer thiefs with a note that says, "Please do not take!" I'm totally kidding, or am I? Wanna steal beer from my home?