Hideo Wakamatsu's Hybrid 2-Way Gear Carry-On (far left, $179;
hideowakamatsu.com) easily converts from a traditional wheeled carry-on to a backpack, while Travelpro's Platinum Magna 21-inch Expandable Spinner Suiter (left, $200;
Amazon.com) has a smart wheel design that automatically realigns to change direction when you do.