A lot of long distance through-hikers on the Appalachian Trail here in the Eastern US use hammocks instead of tents. They're gotten a lot more popular due to the "lightweight" craze in backpacking (trying to shave every ounce off your full pack weight) and set up/break down a lot faster.
How do you use the hammocks in the snow though? (Don't know if this applies to the Appalachian Trail, but I know that sleeping in the snow happens on the PCT).
You use both an under quilt and a top quilt to insulate the hammock, which is of course suspended above the snow. I haven't tried that yet as I'm more of a fair weather camper, but comments on various hammock forums suggest that winter camping in hammocks is common.
