Must-Have Gear: Spring/Summer Sometimes good ol' human ingenuity trumps the power of high technology. Take, for example, an avalanche backpack that uses a simple fan to inflate its airbag, eliminating the need for heavy and complex gas canisters. Or a stove that gets better cold-weather performance by turning its fuel upside down. Or a headlamp that better illuminates by letting its lens float. To be sure, this season's best gear has plenty of gee-whiz technology behind it, but its great ideas are leading the way.