Outside the ARG, it has also been confirmed that the FDA has approved a similar microchip implant that goes by the name of Verichip. The chip is currently being used as a means to identify medical patients but is also used to gain entrance into certain nightclubs in parts of Europe, most notably, Barcelona Spain.
For the moment it does not have GPS capabilities but a new version featuring GPS is said to be in the early experimental phase.
www.verichipcorp.com