There's plenty of weight to shed in sleeping bags, especially when it comes to down-filled bags. Marmot’s Hydrogen ($349), for instance, is rated to 30 degrees and weighs a mere 1 pound 8 ounces. Mont-Bell’s stretchy, comfortable U.L. Super Spiral Down Hugger #3 ($339) has a similar temp rating and weighs in at 1 pounds 6 ounces. And if the lower cost of a synthetic-fill bag appeals to you, take a look at Mountain Hardwear’s UltraLamina 32 ($220). It's rated to 32 degrees and weighs 2 pounds.