Well, I've worked on one such geolocation device about the size of a grain of rice, and that was 30 years ago. It was a tracking device started by a former Isra

Well, I've worked on one such geolocation device about the size of a grain of rice, and that was 30 years ago. It was a tracking device started by a former Israeli military intelligence officer after his family was scattered in a terrorist attack and it was days before everyone could be accounted. This tracking device was the size of a pack of cigarettes' when in development, and by the time I left the company (late 1990) the company was being sold to the Israeli government and the device was the size of a grain of rice. It provided 3D location in an area via 3-way triangulation of telecommunication tower signals.