Stick it in your ear

The tubular crest that runs over the top of your ear is known as the helix. It's quite distinctive, even if it doesn't posses the pointy bit that proves you're descended from a monkey (lookup Darwin's tubercle), or a Vulcan. Best of all, it doesn't change as you age, unlike the iris, which along with the face are the most popular means by which machines recognize humans.

The problem is, getting a computer to find and recognize the ear. Fortunately, researchers in the School of Electronics and Computer Science of the University of Southampton have come up with a means for identifying ears with a success rate of 99.6%