another random user writes with news of a patent application from Microsoft that details a method for silencing your phone by giving it a whack. "There are a variety of circumstances under which it may be desirable to quickly control a device without having to interact with a traditional user interface. For example, often mobile device users forget to set their mobile devices in a silent or vibrate mode and the device rings or makes sounds at an inopportune moment." And yes, 'whack' is the technical term used in the patent (20120231838): "receiving information indicative of acceleration of the mobile communications device; determining correlation between the information indicative of acceleration of the mobile communications device and exemplar whack event data; and based at least on the correlation, controlling an audio signal of the mobile communications device." This method is not recommended for controlling the audio output of animals or children.