1. An air conditioning system including multiple thermostats disposed at predetermined locations throughout a building defining enclosed spaces and for controlling an air conditioning unit, said multiple thermostats each including a temperature display and switch actuators for setting a temperature setpoint, said multiple thermostats including control circuits, respectively, operably in communication with each other such that changing a temperature setpoint at any one of said multiple thermostats will change the temperature setpoint of all of said thermostats wherein each of said multiple thermostats include a Control Here switch actuator operable to effect control of said air conditioning unit to control the temperature in accordance with the temperature setpoint at the thermostat at which the Control Here switch actuator has been most recently actuated and to control the temperature in response to a temperature sensed by the thermostat at which the Control Here switch actuator has been most recently actuated.