A method and apparatus for changing an operating state includes a portable electronic device determining that the portable electronic device is in a first position for which a display face of the portable electronic device is directed upward with respect to a downward-directed gravitational field. The method also includes determining that the portable electronic device is undergoing rotational motion through a curved trajectory that takes the portable electronic device from the first position to a second position and determining that the portable electronic device is in the second position for which the display face of the portable electronic device is directed downward with respect to the gravitational field. The method further includes responsively changing the operating state of the portable electronic device from an active state to an inactive state.