I'm only half joking - I was on a Continental flight some years ago with a 5 hour delay, no bathrooms, and the passenger sitting next to me peed into another passenger's water bottle for relief. There was simply no choice, and for all I know the flight crew emptied other containers for other passengers to use. Since then I have never gotten on a flight without an empty bladder.

Years before that experience I also remember a flight in the days of the USSR from Tashkent to Kiev where the bathroom erupted and was totally unusable let alone approachable on foot, and Soviet citizens - who knew well the odds that the plane might crash, and had come on board stinking drunk - were peeing in vodka and orange drink bottles. The stench was terrible, so peeing passengers was the least of our problems.

Good times...