This is just a showcase for now, but if enough people really want it, I may make a tutorial.
This device jams the 27MHz band, which is used by Radio-Control (RC) Boats, Drones, Planes, and Cars. It clogs up the band with a common "go right" signal at full speed. If the vehicle you are jamming does not read that type of signal, it'll either do something else or most likely just stop altogether. This fits in your pocket and is powered by three AAA batteries, and the little hole on top is where the button is. There's a wire antenna that runs the length of the outside of the box, and if you put your hand on it, you can get a good 40 feet of range! Also, it has the ability to hijack any 27MHz RC remote signal. This means that you can stand next to the operator of whatever you aim to jam, turn on the jammer, and the remote that the operator is using will now send out YOUR signal. This is fun at RC races or anywhere else you stumble upon someone using their little RC toy... especially if it's a boat, in which case this will make it go right at full blast until it crashes into something and sinks >:)