In a previous column, I covered two major companies, Kelty and JanSport, who will introduce retro-style, external-frame backpacks in 2011. The article pitched external-frame packs as throwbacks—bulky, exposed and skeletal products that were left behind two decades ago by anyone serious about carrying loads in the great outdoors.But the external-frame lives on, and it’s not just for the retro crowd. A new entry in the category, High Sierra’s External Frame pack series, include the classic exposed-frame look but with modern touches including hydration-reservoir sleeves and eco-minded PVC-free construction.One pack in the High Sierra line, the Foxhound 50, has a top-load main compartment, contoured straps, and a mesh panel to let air flow between your back and the pack load. There is a removable media pocket on the front to store a GPS unit or an iPhone. It costs $110.High Sierra is hardly the only company in the external game. In addition to their retro lines, Kelty and JanSport sell modern external-frame models. Other companies that sell externals include ALPS Mountaineering, Mountainsmith, Coleman, Texsport, Cabela’s, and Outdoor Products.ALPS, a small company in rural Missouri, offers two external models. The Red Rock, a 2,000-cubic-inch model, costs $89.99.Outdoor Products has a couple packs in the category, including the bargain Dragonfly External Frame Youth Pack. It costs as little as $39.99 on web retailers like Campmor.com and features a plastic-composite frame.Coleman’s Bozeman X 60 has water repellency and a slick, modern look with silicone-treated nylon in a diamond rip-stop pattern. It costs about $150. There is an adjustable torso pin-and-ring system for positioning the frame and pack on your back.The Scout model from Mountainsmith, made for youth, costs $109 and is marketed as offering a “supportive external frame that provides a comfortable backpacking experience for kids.” Its frame is made with 6061 aluminum and it has a “sleeping bag sling,” which looks like a small hammock hanging on the bottom of the pack.Why go external? Cheaper price is a good place to start. To be sure, you can find deals on internal-frame packs. But at retail, external-frame packs are often cheaper than comparably-sized internals.For hot weather, externals can be a good option. With a frame propping the load away from your back, air flow is increased.Some backpackers claim externals offer better support with heavy loads. The packs can sit high and tower up behind your head, offering a higher center of gravity for the load.One thing is for sure: As a backpacker, with an external-frame pack you will stand out. The exposed-frame look is one of a bygone era in the backpacking world. Could these special packs make a comeback? Seems a few big companies are betting externals can.—Stephen Regenold is founder and editor of www.gearjunkie.com.