Tired of the agony of placing one foot in front of the other all on your own? A new boot is coming to the rescue: It improves the efficiency of the human stride by 7%, as the BBC reports, "showing that there is room for improvement in our already very well-tuned gait." The device acts as an exoskeleton, using a ratchet and spring system to make it feel as though you've dropped a 10-pound backpack, researchers say