Let's add to all the bizarre methods currently being researched for the future computer, shall we? A compound in Prussian Blue, named because it was used to dye uniforms for the Prussian army, can be magnetized. It can therefore be used as a switch, flipped one way by light and flipped the other way by heat, according to researchers at the University of Paris: "Such compounds, which can memorize binary information, could be used as storage bits for future computers."
Want the specifics? The researchers first replaced some of the iron atoms in Prussian blue with cobalt atoms. Then, they illuminated the substance with a red light at -150 C, causing the compound to shift and become magnetic (on). The change is stable. With heat, the compound can become non-magnetic (off). The researchers believe that magnetism can occur because of a single electron that moves back and forth between the cobalt and the iron.
News source: CBC News