1. A computer-implemented method, comprising: at a portable electronic device: detecting with an accelerometer associated with the device a movement of the portable device; determining whether the movement is due to a predetermined type of user gesture exerted on the portable electronic device, wherein the predetermined type of user gesture is a smack exerted on the portable electronic device; and if the movement is due to the predetermined type of user gesture and the portable electronic device is emitting an audible alert signal, silencing the audible alert signal and, in addition to silencing the audible alert signal, at least one of: silencing subsequent audible alerts for a predetermined period of time; silencing subsequent audible alerts of a similar alert category for a predetermined period of time; and placing the portable device into an inaudible alert mode.