I adore spending time outside. Winter means skiing under sunny skies, but summer is my favorite because there’s more variety of outdoor adventures. Weekends are spent hiking, backpacking, and lounging at the lake before getting a beach bonfire roaring around sunset. But there’s one downside of spending all day outside — it can be hard on your body, especially when you’re sitting on uneven ground or hard picnic tables. Perching on a stump at a campsite is uncomfortable after about 10 minutes, but bulky camping chairs are difficult to carry. And if you’re backpacking — camping for days in a row with all your gear on your back — there’s no way you can carry the extra weight of a chair.  That’s why I’m beyond glad that I stumbled on Hummingbird Hammocks, a company that makes hammocks out of ultralight parachute fabric. I have the Ultralight Single Hammock ($65). The combined weight of the hammock and straps is just seven ounces and the hammock packs into a bag smaller than your palm. The incredibly low weight should please backpackers — it’s much easier to carry than a bulky folding chair. It’s small enough to toss into a purse b...