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.
glow in the dark slime.Another pinner says: glow in the dark slime UPDATE: made this and it was every bit as cool as I had hoped. Not sticky (was afraid it'd be sticky on the hands) and therefore not messy. and it glows!
a 'calm down jar' - shake the jar and the child has to watch the jar until the glitter settles. great alternative to using 'time out' as calm down time. Great idea till the kid throws the jar cause they are mad. Plastic jar would be a must.