Really Cuts the Grease: Three students from The University of New South Wales have developed a dishwasher which dissolves grease and dirt from dishes using supercritical CO2 gas. Carbon Dioxide goes supercritical at very high temperatures and pressures, and is being considered by NASA as a method for dissolving fuel and water out of rocks on Mars. If that's just a little too spacy for you, IDFuel's got some more down-to-earth, but still super cool home appliances.
