The Barcode of Life
Since DNA is digital information, it is, essentially, a number. A very, very, very big number. And because nearly every cell in a living thing contains the same genome, unique to the individual (leaving aside twins etc.), in principle this means that every being is barcoded in every cell.
Of course, in practice, this isn't much help, since sequencing is still pretty costly. But we don't need all those several million/billion DNA letters to barcode life: a few hundred will do, if chosen judiciously.
That's precisely what the group with the wonderfully literal name of "The Consortium for the Barcode of Life" has come up with. This Wired report brings us up to date on the bird part of the project (there's a fishy one too) that will eventually turn every species - if not every individual - into a number. That's a later project that governments around the world will carry out as a follow-up (did anyone say ID card?).