Created by Aleix Lovet and Xavier Salueña of the Polytechnic Institute of Catalonia, the DAlH2Orean has the honor of being the world's first remote-controlled car to run on aluminum soda can tabs. Essentially, the car uses hydrogen power generated from a chemical reaction in which the aluminum tabs are mixed with a solution of sodium hydroxide and water. The hydrogen generated from this reaction powers a hydrogen fuel cell, which in turn powers the car. The energy is clean, with no CO2 emissions at all. The full reaction is slightly more complex than that, involving a few filters (silica gel to remove moisture, vinegar to remove hydroxides), but that's the basic idea.