An audio/video source switching system comprising a control server, a computer network (102, 202), at least one mobile device, and a switcher, wherein the switcher comprises: a microprocessor; a memory; computer-readable instructions stored in the memory and executing on the microprocessor; a plurality of audio/video source inputs (308, 504, 508, 511); an audio/video output (304, 510); and one or more computer network interfaces (105, 201); wherein the switcher is configured to receive a control frame comprising a control instruction from the control server via the computer network (102, 202), and in response to the control instruction, to enter one of an update mode, active mode, and passive mode in accordance with the control instruction; wherein the update mode obtains audio/video data and updated computer-readable instructions from the control server via the computer network (102, 202) and to store the audio/video data and updated computer-readable instructions in the memory of the switcher; wherein the active mode disconnects a first audio/video source input from the audio/video output and connect a second audio/video source input to the audio/video output; and wherein the passive mode listens for a control frame from the control server or for an audio streaming request received via the computer network (102, 202) from the mobile device, and in response to the audio streaming request, to stream an audio component of an audio/video signal emitted from the audio/video output to one or more mobile devices via the computer network (102, 202); wherein if a control frame received in the passive mode instructs the switcher to enter in active mode, the switcher is configured to automatically detect a change in a first audio/video signal received via a first audio/video source input, and in response to said detection of the change in the first audio/video signal, to disconnect the first audio/video source input (308, 504, 508, 511) from the audio/video output (304, 510) and connect a second audio/video source input (308, 504, 508, 511) providing a second audio/video signal to the audio/video output (304, 510); and wherein the first audio/video signal comprises a broadcast television signal comprising a first television program segment followed by a first commercial advertisement, wherein the change in the first audio/video signal is a transition from the first television program segment to the first commercial advertisement and wherein the second audio/video signal is a second commercial advertisement different from the first commercial advertisement. a microprocessor; a memory; computer-readable instructions stored in the memory and executing on the microprocessor; a plurality of audio/video source inputs (308, 504, 508, 511); an audio/video output (304, 510); and one or more computer network interfaces (105, 201); wherein the switcher is configured to receive a control frame comprising a control instruction from the control server via the computer network (102, 202), and in response to the control instruction, to enter one of an update mode, active mode, and passive mode in accordance with the control instruction; wherein the update mode obtains audio/video data and updated computer-readable instructions from the control server via the computer network (102, 202) and to store the audio/video data and updated computer-readable instructions in the memory of the switcher; wherein the active mode disconnects a first audio/video source input from the audio/video output and connect a second audio/video source input to the audio/video output; and wherein the passive mode listens for a control frame from the control server or for an audio streaming request received via the computer network (102, 202) from the mobile device, and in response to the audio streaming request, to stream an audio component of an audio/video signal emitted from the audio/video output to one or more mobile devices via the computer network (102, 202); wherein if a control frame received in the passive mode instructs the switcher to enter in active mode,