Turn a Raspberry Pi into an FM transmitter
As an amateur radio operator, I think this is fascinating, because they claim it can transmit on the 2m VHF band (144-148MHz) that's popular among hams.But I have some concerns about its signal characteristics, since you're essentially abusing digital hardware (GPIO) to produce a modulated output it wasn't designed to produce. Someone with a spectrum analyzer should check to see if it produces any nasty harmonics, or similar noise, that could interfere with other stations.