A new approach to memory devices stores ones and zeros on individual molecules. Fraser Stoddart and collaborators at the University of California in Los Angeles have shown that individual organic molecules called catenanes, held between carbon nanotubes and metal electrodes, can be used to store data. Each catenane molecule has two linked rings that can rotate relative to each other depending on an applied voltage. The nanotubes act as incredibly thin wires, and also bond chemically to the catenanes. These memory elements can be very small - a gramme of organic molecules could, in principle, be enough to make all the memories for all the new computers worldwide for several years.
Further reading
A Goho 2003 Science News 164 182.