Here is a sure fire way to WOW this Summer! Make your own glow in the dark chalk using only two ingredients plus water. This chalk glows in the dark, under UV light, and it even works in broad daylight! (SUPER Summer FUN from Growing a Jeweled Rose)
Make colored sand art by stirring a chalk stick in a bowl of salt. it changes the color. Stir less for light color and more for dark richer color. (I used to do this with salt and food coloring. but the chalk stick idea is brilliant!
Sidewalk Chalk Spray-All you need is Flour, Food coloring, and Warm Water. A tablespoon of flour, 10 drops of food coloring, and about a half cup of warm water. Shake it up in the bottle and let your kid go nuts.