My boys were sick this past week with fevers, so I pulled out the old crib mattress from the garage for them to lay on in the living room. Now that they are feeling better, they found out it makes a great trampoline also.
After five kids, the crib mattress is not in great shape to pass down to anyone. I discovered last winter, when they were sick with the stomach bug, that I could lay the mattress in the bathroom. That way they could sleep in there and be close to the potty. I then stored the crib mattress in the garage for those sick days. You could also store your old crib mattress under a bed too.
I am so glad they are feeling better and will let them have fun with the mattress for a couple of days.
What item did you re-purpose after you kids out grew it?