For camping or late nights at the beach? Leave 1/4 of Mountain Dew in bottle (just don't drink it all), add a tiny bit of baking soda and 3 caps of peroxide. Put the lid on and shake - voila! Homemade glow stick (bottle) solution.
"Sun prints" - Lay construction paper outside in the sun. Arrange items on the paper so their silhouettes will look nice. Wait about an hour and remove the items. You will see the paper has faded around the objects. Then laminate for placemats!