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.
Want a fun way to encourage kids to do their chores? Craft a chore door knob hanger. Door hanger that says "to do" and "done". Clothes pins with the chore are on the "to do" side and when the child does the chore move they move it to the "done" side.
This is brilliant! And so simple! (For old pallets in the yard!) Wow, this would have been the location of so much play wguyhen I was a kid. We did so much An old pallet! pretending to be in the middle of the ocean, or lava, or what-have-you.