"There's a rainforest of bacteria on your skin," researcher Noah Fierer, an assistant professor of ecology and evolutionary biology at the University of Colorado at Boulder, tells the Los Angeles Times. The human hand may harbor 100 different species of bacteria, and each one is unique, with its own signature. Roughly 13 percent of the makeup is shared between any two people. Eventually, technology could be developed to identify each individual by such germprints, a handy tool, say, if a criminal happens to be wearing gloves. Or fiddling around with your computer, as Wired notes. Co-researcher Rob Knight joins Fierer in writing, "The results demonstrate that bacterial DNA can be recovered from relatively small surfaces, that the composition of the keyboard-associated communities are distinct across the three keyboards, and that individuals leave unique bacterial ‘fingerprints’ on their keyboards."