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.
Bubble Wrap Run: Simple Indoor Fun! I used several separate pieces of bubble wrap with duct tape. (side note - duct tape doesn't leave any residue on pergo :)(Make sure to tape down all sides!) The bigger bubble wrap works better than the smaller.