The governments of Singapore and the European Union are trying to develop a computer chip the size of a single molecule. From Singapore's press release on the subject:
http://www.a-star.edu.sg/?TabId=828&articleType=ArticleView&articleId=1393 via Glenn Reynolds | Photo (unrelated) via Flickr user Fabrizio Sclami used under Creative Commons license
A*STAR’s IMRE and 10 EU research organisations are working together to build what is essentially a single molecule processor chip. As a comparison, a thousand of such molecular chips could fit into one of today’s microchips, the core device that determines computational speed. The ambitious project, termed Atomic Scale and Single Molecule Logic Gate Technologies (ATMOL), will establish a new process for making a complete molecular chip. This means that computing power can be increased significantly but take up only a small fraction of the space that is required by today’s standards.
The fabrication process involves the use of three unique ultra high vacuum (UHV) atomic scale interconnection machines which build the chip atom-by-atom. These machines physically move atoms into place one at a time at cryogenic temperatures. One of these machines is located in A*STAR’s IMRE.
http://www.a-star.edu.sg/?TabId=828&articleType=ArticleView&articleId=1393 via Glenn Reynolds | Photo (unrelated) via Flickr user Fabrizio Sclami used under Creative Commons license