A portable GPS/radio unit communicates over a wireless radio network with at least one other unit which is transmitting radio signals over the network indicative of that unit's location. The GPS/radio unit comprises a GPS receiver for receiving satellite signals from a plurality of satellites, a radio receiver for receiving the radio signals transmitted by the other unit, a processor for calculating the unit's location as a function of the received satellite signals and for identifying the location of the other unit based on the received radio signals, and a display for indicating the location of the other unit. The display may indicate the respective locations of multiple units and may also display unique identifiers for each of the units. A system and method for indicating the location of one portable GPS/radio unit on the display of another portable GPS/radio unit involves at least two such units communicating with one another over a wireless radio network.