Living things don't get a whole lot humbler than a bacterium, with its few hundred thousand genetic base pairs and its stripped-down physical design. Still, you try inventing one. That's what geneticist J. Craig Venter one of the two men credited with mapping the human genome managed to do. Venter stitched together the 582,000 base pairs necessary to invent the genetic information for a whole new bacterium. Step two is to boot up that DNA programming in a living bacterium to see if it takes charge of the organism. That's next on Venter's agenda and he has little doubt it will work. As any software designer will tell you, once you know how to write the code, you can make it do almost anything.