I got a couple of these for my nephews for Christmas.
"Developed by educators at the Lawrence Hall of Science, Sunprints encourage an interest in the photographic process using only sun, water and a bit of imagination. Place a fern, flower, or other object on the special paper and set it in the sun briefly. Then rinse the paper in water and watch as a beautiful, long lasting image appears."
The kits were developed in the early 70's. It's weird to think about how much the "photographic process" has changed since then.