The dual-flush toilet is a great conservation invention. With a 0.8-gallon flush option—half the amount of a standard flush—it can save a family of four up to 6,000 gallons of water per year. Dual-flushers typically cost upward of $500, but Sterling's models (there are four) conserve your money, too. The units, all with two-button actuators, start as low as $229. And they qualify for water-conservation rebates, so depending on your jurisdiction you could get some of that cash back.
Kohler, Wisconsin; 800-783-5464