Osprey Outlander 90; ospreypacks.com
The 5,500-cubic-inch Outlander 90 is a backpack that doubles as a duffel bag (it's been revised as the 4,900-cubic-inch Waypoint 80' not shown). Both packs offer the same cool features, but the Waypoint is a more streamlined unit. When flying, tuck the harness system (identical to top-end Osprey packs) behind a zippered panel and use the side handle for carrying. In backpack mode, there are plenty of exterior straps for securing trekking poles, tents, or sleeping bags. Interior mesh pockets help organize belongings, and stiff foam sides protect everything.
gripes: Wheels would make this one even more versatile.
props: A 900-cubic-inch detachable daypack has space for basic necessities.
Dana Design Far Flung (top) $250; danadesign.com
Whereas the Osprey Waypoint becomes a duffel, the 3,100-cubic-inch Far Flung includes an attached 5,200-cubic-inch duffel (hidden in a stow pocket). When checking in, unfurl it and toss the pack inside - there's still enough room for boots, snowshoes, and a sleeping bag. When it's used as a pack, there are convenient pockets for travel docs, wallet, and sunglasses - as well as a breathable back panel. Remove the daypack, and both pieces become carry-on legal.
gripes: Unlike the Osprey, this detachable daypack doesn?t have a waist belt and isn't as ski-worthy.
props: The Far Flung is more SUV than minivan: Its trail-ready harness system is extremely comfortable, and designed with overnight camping in mind.