The ability to accurately pinpoint the point of origin of an emergency call can greatly increase response times of emergency services. Emergency calls made from cellular phones can only be traced by the Global Positioning System (GPS) or cell-based positioning, which are sometimes unacceptably inaccurate; they cannot provide information on, e.g. the exact floor of a building and also suffer from blind spots. We have been developing a system that can determine the location of a cellular phone using in-built passive or active radio-frequency identification (RFID) readers and GPS receivers. This paper introduces the outline of the prototype system.