Charter a helicopter and drop all of them from 1,000 feet.
Growing up I always had this dream of being able to drop a boulder from a helicopter into the ocean to see how big of a splash it would make; I can only imagine how high these balls would bounce, or the sound it would make as they all hit the ground. (Apparently this was already done, sort of).
Random, I know, but that's what I would do.
How about you? If you found this amount of balls and had the free-time to do something with them, what would you do?