Or, perhaps, drinking?
Reef, the flip-flop maker that brought you sandals with integrated bottle openers
now brings your a flip-flop with integrated flask.
(It's difficult to see in this product shot, but there's a 3-ounce pouch for the liquid of your choice buried in the foam, mid-sole.)
Buy both styles, pair one with the other, and you'll never go thirsty again.