The most prolific car manufacturer on the planet resides in a Rice University laboratory in Houston, where chemist James Tour and his colleagues have built one trillion trillion nanoscopic cars. The tiny four-wheeled vehicles are only four billionths of a meter wide-25,000 of them parked side by side would be about as thick as a piece of paper. Not just another nano-gimmick, Tour´s cars could one day carve tiny channels in silicon, creating more-powerful computer chips.