Lemon Joule Thief
From the MAKE Flickr photo pool

Like some sort of cyborg fruit-turned-electronic hedgehog – Flickr member s8’s 2-week old lemon-powered joule thief is showing its age. Hmm. I wonder if it smells as good as it looks. – middle-aged lemon

HOW TO – Tiny AVR Microcontroller powered by fruit

Make a Joule Thief – Weekend Projects Video Podcast