ZDNet reports that Harvard Medical School CIO John Halamka has had an RFID chip implanted in his arm. According to a video interview given by Halamka:
"I felt the only way to really understand the pros and cons of the technology would be being an early adopter myself," Halamka explains during a CIO sessions video interview. "Were spending vast amounts of money and hurting a vast number of patients in this country because were just not delivering healthcare accurately enough."
I presume that an implanted RFID wouldn't be the only way to make sure that the Harvard hospitals don't mistakenly treat the wrong person.