Israeli scientists have devised a computer that can perform 330 trillion operations per second, more than 100,000 times the speed of the fastest PC. The secret: It runs on DNA.
A year ago, researchers from the Weizmann Institute of Science in Rehovot, Israel, unveiled a programmable molecular computing machine composed of enzymes and DNA molecules instead of silicon microchips. Now the team has gone one step further. In the new device, the single DNA molecule that provides the computer with the input data also provides all the necessary fuel.

The design is considered a giant step in DNA computing. The Guinness World Records last week recognized the computer as "the smallest biological computing device" ever constructed. DNA computing is in its infancy, and its implications are only beginning to be explored. But it could transform the future of computers, especially in pharmaceutical and biomedical applications.

National Geographic News
Alot more information at the source. Kinda cool. If you PC runs out of juice, just pour some or your own blood into it