Among the handiest accessories for backpacking are waterproof compression stuff sacks. They are great for compressing your clothes into a manageable size for easy packing or to make a bulky sleeping bag fit inside your pack.
My favorite new compression sack is the Granite Gear AirVent DryBloc Solid ($23-$34; www.granitegear.com). They are ultralight, ranging from 2.8 to 3.8 ounces (about half as light as most sacks on the market) and come in four sizes from 7.8 liters to 23 liters. They’re waterproof too with sealed seams and a roll top closure. You just stuff your sleeping bag inside and start squeezing the air out to make it as small as possible. A breathable membrane panel made with eVent fabric is positioned at the bottom so it allows air to escape while still being totally waterproof. Finally, you roll the top, snap the buckles and start tightening down the four compression cords (they replaces straps with lighter-weight parachute cord) until your sleeping bag is small enough to pack.
While most compression sacks are round, Granite Gear’s are thoughtfully-shaped blocks which maximize packing space because they fits better inside the backpack’s corners.