Weather: Fill the cup with water. Put shaving cream on top for a cloud. Explain that when clouds get really heavy with water, it rains! Then put blue food coloring on top of the cloud, and watch it rain.
Make your own shaving cream. Note to self: this recipe makes for an awesome shave but is very runny. I'm trying more of the thicker ingredients (conditioner & lotion) to see if it holds together a little better instead of turning into soup.