Temporary tattoos for kids.when you are on vacation, or amusement park. Provides ID/contact info if lost. What a good idea. I've seen ppl do this with pen but what a good idea to do with a temp tattoo!
How to keep a child busy for hours in the summer: DIY: Giant Ice Cube Awesomeness - filled with plastic animals, dinos, and such. And I'm sure you could put in food dye before its frozen to color it like the ice block in the photo.