Turn the classic 70's wireless toy into a modern high-tech spy device. I never picked up any chicks with it anyway. Watch the video and see the test results at the end. What I heard surprised me! This is a modified version of a similar article in "Sneaky Uses For Everyday Things".
A vintage Mr. Microphone FM modulator. These were designed to transmit your voice over the low end of the FM band, around 88MHz. These are not easy to come by but you can find them at garage sales and occasionally on Ebay.