If the "if it's yellow let it mellow" debate still rages in your home, have we got the solution for you: a waterless urinal. Though most often relegated to restaurant bathrooms and the like, urinals in the home make tons of sense: they save thousands of gallons of water and you don't have to worry about remembering to put the seat down. Add the waterless -- as in, no flushing required -- element and you've got a device that conserves a remarkable amount of water. Take this sleek option from Kohler (above); it's tubular design is not only a refreshing take on the more typical blocky designs, but it "virtually eliminates splashing". Because you don't have to flush it (more on that in a sec), it saves an astounding 40,000 gallons of water per year.
The "waterless" part of the design works like this: there's a "trapway" at the base of the urinal, in which the "sealing liquid" goes; since it's less dense than liquid waste, once your pee goes through, the liquid stays at the top of the trapway, providing a barrier that blocks odors and keeps maintenance to a minimum.