From the MAKE Flickr photo pool
Member Laen built this LED birthday candle, “Made from a home-made flip-flop circuit, a pill bottle, and some foil.”
The foil protrusion at the top may look like a wick, but it’s actually a contact for a breath controlled switch – if it’s blown into contact with the left side, the LED below turns off; blow it to the right and the circuit resets turning the light back on. Clever design!
Check out Laen’s photo set for more details