LED throwies are an inexpensive way to add color to any ferromagnetic surface in your neighborhood. A throwie consists of a lithium battery, a 5 mm LED and a rare-earth magnet taped together – estimated total cost is less than US$1.00 per throwie. Throw it up high and in quantity to impress your friends and city officials. They're also easy to modify - turn them into floaties, underwater jellies or weatherproof lanterns, impressing al kinds of officials.