Advocates of "body hacking" will gather in Austin this weekend to promote everything from bionic limbs to human microchips that can serve as anything from identification to a car key... Goodman showed off his own most recent "hack," a radio-frequency identification (RFID) chip in his left hand. It's the same technology veterinarians implant into pets as a way to identify dogs and cats, but humans are using them to make their lives simpler or, in some cases, safer. "You can log into your computer, you could open your doors" with the chips, Goodman said. "I know people who start their...