Light Trix are LED light up thumb-tips. Slip one onto each thumb and you can make it light by giving it a squeeze and the light goes off when you let go.
Passing the light
To pass the light from one hand to another, you just have to release one thumb at the same time as lighting the other. Practice this in front of a mirror for a minute and you'll be able to make it look very convincing.
Vanishing and appearing lights
To produce light, you can grab at the air or pretend to pull the light out from a nearby light. To make it vanish, you can throw it away or pretend to put it back. You can even pretend to swallow it - just don't actually swallow the Light Trix thumb (You'll choke).
Lighting objects up
While holding an object like a paper bag, a glass of water or some other transparent object, You can make the object illuminate by squeezing your thumb against it. This leaves your other hand free to grab, throw, wave and catch lights however you like.
Keeping it secret
The thumb tips are thumb shaped but if you wear them all the time, people are going to notice that they're a little strange. They're very easy to slip on inside a pocket when you need them and, while they're on, keeping your hands moving - even slowly - will make them difficult to spot; especially when they're illuminated.