I've just stumbled upon
this kickstarter.
The idea is to insert a little nozzle-like adapter to a faucet, which makes it spray
water into fine mist.
They claim it takes 98% less water.
I guess there's a chance that this might take a little bit more time to wash a dish, in which case the 98% would be a little exaggeration. But I think it would still save a good amount of water.