A team of researchers from Yahoo Labs has developed a much affordable alternative to fingerprint sensors for phones. It's a biometric system called "Bodyprint," and it only needs devices' capacitive touchscreen displays to authenticate body parts. Since displays have lower input resolution compared to specialized sensors, the system requires you to use larger parts of your body. It can recognize your ear, fist, phalanges, set of five fingers and your palm -- simply press any of them on the screen for access. In addition to serving as your phone's gatekeeper, it has a number of other potential applications, as well.