I'm preparing for a section hike of the Appalachian Trail, but wanted to mention a new lightweight cottage manufacturer: http://katabaticgear.com/. Katabatic Gear sells lightweight down sleeping bags and bivies made of the decent fabrics and materials (Pertex and 850-down). They also sell lightweight down hoods which have turned my interest a bit in recent months. Oddly enough, I think pricing isn't too bad either. I've never tried their products nor do I know anyone who has, but I figured I'd throw it out there and hopefully get some feedback.