Down the rabbit hole, there is a realm of ridiculously light gear that actually works. Add to that list the Sea to Summit Ultra-Sil DayPack, a 2.4oz - yes, you read that right - pack that stuffs down to about the size of a compact camera. A small compact camera.
The DayPack stuff sack is permanently attached to the inside top of the pack, serving double duty as a an internal pocket for keys and credit cards. The pack is the size of a standard school daypack, 20 liters, big enough for a day of fastpacking or travel use at the beach or market.
The entire pack is made from siliconized Cordura ripstop nylon, tough as nails: we shoved sharp-cornered books inside and humped them around with no sign of wear. Even after two months of reefing on it the DayPack is laughing at us. Seams are reinforced with bartacking, and when stuffed there's a little cord loop for attaching to a key ring or carabiner. The shoulder straps are about 2.5 inches wide at the top, and even with loads of 15 pounds are plenty comfy. The half-moon top zipper gives easy access to everything inside.
The only nit to pick is the adjustments on the shoulder straps. They don't lock very well, although you can easily throw a knot on it when you've got it where you want it. This is an awesome piece of gear, perfect for light backcountry and travel use to hold layers, lunch and other essentials. Sea to Summit seems to have this material fully dialed in and they're creating all kinds of cool stuff so stay tuned.