Abstract: A mobile user device, such as a personal digital assistant (PDA 100), a wireless telephone, a car phone, or any other programmable device that the user generally has with him or her, is equipped with a global positioning system (GPS) receiver (101) and is programmable (102) by the user to alert the user to when he or she arrives with the device at a predetermined location (252), as well as to disclose (101) to the user whatever information (263) the user chose to associate with that location (e.g., a “to-do” list). The user can program in the geographical coordinates (253) of locations and location names (252), and thereafter refer to the locations by name. The user can also program in a range (254) around each location, so that his or her arrival within that range will trigger the alert for the location.

Abstract: The low power child locator system consists of a lightweight, low power radio frequency transmitter beacon worn by the child and a radio frequency directional receiver that can be used to direct the user to the radio frequency beacon transmitter. The transmitter can be programmed to generate a unique signal to prevent its output radio signal from being received by another receiver. The transmitter-receiver pair therefore communicates to the exclusion of other transmitters and receivers that are operational in the vicinity of the transmitter-receiver pair. Since the child is assumed to not have traveled a great distance from their original location, the radio frequency directional receiver operates as a simple signal strength indicator, using a plurality of narrow beam antennas to enable the user to vector in on the transmitted signal.