Your new iPhone 5s (okay, we don't have one yet either) is equipped with fancy fingerprint recognition technology called Touch ID, which allows you to unlock your phone with one of five registered fingerprints. In theory, your four fingers and a thumb. (Or your partner if you're that trusting.)
A few curious types have naturally experimented with other appendages like the side of your hand, toes (which, okay, makes sense for someone who might not have the use of their hands), cat paws and... nipples. See the magic below.
Toe and Palm Printing
This is Just Weird (Man Nipples)
We've also heard you can imprint your nose on the thing, but we're dubious until we see video proof.