Make a Photon Flower That Lights Up When you drop lemon juice on the zinc nails (covered w/paper toweling &wrapped w/copper wire or foil); LED completes the circuit. Stem & leaves are décor. From Instructables.
Hacking Electronics: An Illustrated DIY Guide for Makers and Hobbyists by Simon Monk. Who needs an electrical engineering degree? This intuitive guide shows how to wire, disassemble, tweak, and re-purpose everyday devices quickly and easily.