Complete instructions for this episode of Weekend Projects can be found at

Learn to build these simple glow-dots in seconds! LED Throwies are fun, easy circuits that quickly stick to any ferro-magnetic surface. Toss them onto pipes, poles, or other surfaces you want to glow! Modify this simple circuit into a giant throwie bug, or hack an on/off tab into your circuit. We’ll also show you how to build casings for your circuits that are both weather-proof and indestructible! LED Lanterns can be sunk in the ground or dropped in a nearby pond which work, and look great, at night.

Take a look at the project page for more inspiring ideas, including morse code throwies, LED Jellies, and Floaties.