I'm sitting here playing with my sleeping bag and a sleeping pad as I wait for my first hammock to arrive. I've put the sleeping pad inside the sleeping bag and as long as I don't try to lie on my face, the pad behaves itself and stays in place. The pad nicely curls up in the foot end of my mummy bag, but lays pretty flat around my shoulders (now I see the need for an SPE or something similar). Has anyone ever tried this before? Just curious.