You probably don't think about this every time you separate your whites, but the U.S. uses more than 330 billion gal. of water on laundry each year, according to the British firm Xeros Ltd. The company is developing a machine that draws cleaning power from reusable, stain-absorbing nylon beads, requiring much less water as much as 90% less than a normal washing machine. (See above for how it works.) A commercial version is due out next year: good news for conservation and your monthly water bill.