Bubble wrap + two kids = 90 minutes of fun.
The dog took himself off upstairs to find a bed and put his paws over his ears - gun dog he aint. It was very loud. Small children jumping up and down on bubble wrap goes bang, crack, snap.
I highly recommend it. They were cackling with laughter and having a great time. And once the stomping, running and jumping were done Isaac lay down and started working his way through the sheet with his fingers.
A mattress has given hours of entertainment too - jumpoline for winter weather.