Scientists at the University of Colorado in Boulder, USA, have discovered that the bacteria on our hands is different for each individual.
(They took swabs from keyboards and were able to match the bacteria they found their to the computer owners. They say that the results could be used in forensic identification, in the same way as DNA. And don't think you can escape with a quick scrub, even scrupulously clean people have about 150 different species of bacteria on their hands. I always knew we had evolved as a complex bug carrier.)