A growing number of people are opting for electronic implants under their skin. These implants work as information storage for things like identification or keys. The implants can be activated and scanned by readers that use radio frequency identification technology, or RFID, such as smartphones and readers that are already used in many office buildings.
Article source: http://www.wsj.com/articles/when-information-storage-gets-under-your-skin-1474251062?mod=WSJ_TechWSJD_moreTopStories
Photo source: By Paul Hughes (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons