Asgard posted his Rapper project in the forum:
What this is, is a small device that records a command sequence for a TV remote control, then emits the same sequence when activated by a pulse detected in a piezo transducer. Such pulse can be as simple as rapping your knuckles on the table where the Rapper is placed. Typically the Rapper would record the mute control for the TV, so that you can run to get the phone without having to hunt down the remote control for the TV. Cute, eh?
nifty :)