This is probably something that you wouldn’t want kids to read about, but it’s still cool nonetheless. Lucid Science is giving ideas on spy gadgets once again, and this time its a tiny FM transmitter. The unit is powered by a 9-volt battery. The design offers a microphone, two transistors, enameled wire for the coil, along with various resistors, capacitors and a potentiometer. The result is a device that can transmit a clear audio signal that you can easily pick up using a standard FM radio. Of course, if you happen to have kids in the house and they read this, you’ll probably end up being paranoid of your room being bugged for a long while.