Methods of providing an estimate of the location of a first device are discloses comprising the steps of determining the location of a separately housed, second device located near to the first device; providing the location of the second device to the first device; and using the location of the second device as an estimate of the location of the first device. Either the second device is arranged to perform a function based on its location other than providing its location as an estimate of the location of the first device, or the location of the second device is provided to the first device using a wireless communications link.