Here's something incredibly funky I came across online. Some Japanese restaurant has created an environmentally friendly food fryer/fish tank. It's supposed to work on the basic principle that the densities of water and oil are different enough to force them to separate. The hot oil on top can fry food. The water, at the bottom, is home to goldfish that eat all of the crumbs that float to the bottom. Cool idea...but there's a lot more I'd like to know. Where do the goldfish poops go? How do you clean the water? Is it possible to change the oil? Despite all of this, it's a pretty nifty concept.