What are uses for foam egg carton mattress pads?

Hi Gina, you could make dog beds, or pillows or cushions for outdoor furniture

Gina: put them on top of your mattress to reduce "friction" and prevent bed sores, etc

If you are not concerned about getting the pad a little dirty, they made great liners for backs of hatchbacks, especially on a road trip. Anything on top of the liner will not slide or bang around. They also help to reduce annoying sounds such as squeaks from luggage rubbing against each other, if smaller cut pieces are put in between the items.

I keep foam mattress pads on hand for extra padding for my re-upholstery projects!!