http://www.psfk.com/2013/06/motorola-password-pill.html
Last week at the D11 Conference, Regina Dugan, head of Google-owned Motorola's research division, introduced an ingestible vitamin prototype that transforms your entire body into an authentication passcode. Made by Proteus Digital Health, the FDA-approved pill contains a small chip that can be switched on and off by your stomach acid. Here's what happens next, once swallowed the pill creates an individual 18-bit signal that would be detectable by external devices like your phone, computer, and even car. The pill also can be taken daily for up to a month.
While the idea of taking pills as verification seems like a major breakthrough, many people might not be interested in taking a tablet that transmits signals from inside their stomachs to log-in into their devices.