Energy-Saving Method

Disclosed is a method to enable a retail display or vending unit to switch to or from an energy saving mode. The method comprises listening for a radio frequency emitted by a mobile telephone and switching the unit from an energy saving mode when a radio frequency is detected and switching the unit to an energy saving mode when no radio frequency is detected. Also described is a retail display or vending unit comprising means to detect a radio frequency emitted from a mobile telephone and means to enable automatic switching off of components and/or processes and systems within the unit when low or no radio frequency is detected and to switch on components and/or processes and systems within the unit when radio frequency is detected.