Caleb Charland made a battery out of an orange:
"Recently one Sunday I spent the day at the kitchen table playing with oranges, copper wires and galvanized nails. My hope was that I could make this on going project work with a single piece of fruit. I tried cutting it into slices and wedges but that ever present voice in my head reminded me the SIMPLER IS BETTER. It only seemed logical to use the orange’s natural wedges as the cells for the battery. The wedges are held up-right with an armature of small wooden skewers. The LED is nestled with in the bounds of the orange wedges. I’m still amazed this worked…though it did require 14 hours of exposure."