Smart folks at Leeds University have found a way to wash a full load of clothes with only one cup of water. Not to mention the clothes come out, practically, dry. Not too surprising since you are only using one cup of water… I spill more than that on myself daily.
The washer works by mixing in a bunch of small plastic chips which absorb dirt. The chips can be used for 100 washes. Expect to see this device as early as next year.