Francesco Capponi has figured out an ingenious way to take eggshells and convert them into pinhole cameras. You only get a single exposure, the result is a permanent image imprinted on the inside of the egg. It's an excruciatingly delicate process, but the results speak for themselves (and would make an excellent project for any leftover blown eggs you have from Easter.)
Capponi started by carving a square opening in the front of the egg, removing the internals, and washing it. Then, in a darkroom, he painted the inside wall with emulsion to make it light sensitive. After that he delicately poked a pinhole in the shell and wrapped the entire egg in black cloth to prevent light from leaking through the shell.
After a 30 second exposure, the eggs were flushed with processing acid, then fixing acid, and what was left behind was a permanent photographic negative, stored on the inner shell. By photographing and inverting the egg, Capponi showed just how much detail these "pinheggs" were able to achieve.
The only problem? The process is excruciatingly fragile. According to Capponi, he broke more than fifty eggs in order to get just four exposures. That's a lot of omelets.