Sort of. The Raspberry Pi CPU had a configurable clock generator that could output up to about 125MHz to a GPIO line. Some people figured out that it was possible to rapidly change the configuration registers to modulate an audio signal onto a carrier frequency in the FM broadcast range. [0] So you could make a low power FM transmitter using just a Raspberry Pi and a piece of wire.

[0] http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...