Just be aware that using the Pi to broadcast FM like that (without additional filtering hardware) produces a lot of noise (it doesn't just broadcast in the inte

Just be aware that using the Pi to broadcast FM like that (without additional filtering hardware) produces a lot of noise (it doesn't just broadcast in the intended frequency, but also a lot of harmonics) and may interfere with legitimate signals. Having said this, we used it for a challenge at a local conference last year to great amusement. :)