It’s hard to be blasé about the Sink Twice. I don’t want to oversell a plastic sink that sits over a toilet tank, but this ingenious, relatively low-cost device could help save the world. Why? Because it saves water. It saves money. It motivates children and adults to wash their hands. It’s a great conversation starter. And it’s really fun, which by itself makes the Sink Twice worth the $83.99 price tag.