Christopher Voigt and his research partners at the University of California, San Francisco, and the University of Texas at Austin hacked the genes of E. coli bacteria, making each altered cell photosensitive. (Voigt is a member of the current TR35, our annual list of 35 exceptional innovators under the age of 35. He and the others were featured in the September/October 2006 issue.) Their first application of the technology, shown in this slide show, was a lawn of bacteria that acts like a photographic plate: when exposed to red light, the lawn reproduces an image inscribed into a stencil held between it and the light source. But this isn't the goal of Voigt's research--it's just an example of the powerful possibilities raised by the young field of synthetic biology. The ability to precisely engineer and control micro­örganisms could lead to new bacterial factories that produce complex drugs or materials.