Neither Arun nor I can remember whose idea it was, but before we realized it, we had placed an order for 9000 plastic balls. The pit was 128 cubic feet which was plenty of room for four or five people. Miraculously nothing of real importance was lost in the pit. The Ballpit was the heighlight of room 329 Keenan, which was featured in Notre Dame magazine and won an Internet dorm room decorating contest.