A system and method are described for providing an indication of the proximity of a moveable device. The system comprises at least a first moveable device having a transmitting means for transmitting data comprising an identification of the first device and a second device having a receiving means for receiving data from the first device and a transmitting means for transmitting data including the identification of the first device together with an indication of the proximity of the identified device. A further device with a receiving means for receiving the data transmitted by the second device can be used in order to obtain an indication of the proximity of the first device. The indication of the proximity of the first device is a scale value which degrades as the first device moves away from the second device.