LED throwies

Powered by a battery. Eventually runs out leaving a light that slowly goes out and flickers. Can be made at home. Useful for site experiments. Has to be attached to a metallic surface. Could be used to highlight parts of buildings that are normally hidden.

A LED throwie is a small LED attached to a coin battery and a rare earth magnet (usually with conductive epoxy or electrical tape), used for the purpose of creating non-destructive graffiti and light displays. Artists use them by throwing individual LEDs onto metallic objects, like public sculpture or road infrastructure. By throwing LEDs onto an object, the object itself acts as a canvas.