1. A method comprising, at a mobile device: subsequent to initiation of a user perceivable output, determining whether said mobile device is in a gesture command input ready state based, at least in part, on a display portion of said mobile device remaining within a threshold angle of a horizontal viewable position for a threshold period of time and an estimated location of said mobile device indicating that said mobile device is in an environment where movements of said mobile device corresponding to gesture command inputs are likely to be distinguishable from movements of said mobile device that do not correspond to gesture command inputs; with said mobile device in said gesture command input ready state, determining whether a detected movement of said mobile device represents a gesture command input; and in response to a determination that said detected movement represents said gesture command input, affecting said user perceivable output.