A communication system is described, including a mobile communications device, a mobile communications base station, and a server computer system. The location of the device may be correlated with certain user preferences stored on the server computer system. The components of the larger system are also described. In some cases, various location related mapping functions for a device are discussed. In other cases, systems and methods which provide for activities to be undertaken based on the location of a device are described. The disclosure also addresses systems and methods of efficiently determining the location of a mobile device. In some cases, different notification schemes based on the location of a device and specified preferences are described. The disclosure also addresses systems and methods for keyword monitoring based on the location of a device.