well I've just been going over my gear list looking for gear that I can use as "multi use". I usually carry a down jacket anyway and I thought it would be nice to have down pants for the cold mornings and maybe I could ditch the sleeping bag altogether to save weight. Its more of just a crazy idea I'm rolling around in my head at this point. Like Tango61 said, if it was effective more people would be doing it I guess. Just wanted to see if anyone had tried it before.