Four-legged, go-anywhere robots aren't really affordable... not unless you're willing to spend as much as you would on a used car, anyway. Ghost Robotics, however, thinks it can do better. It's working on the Ghost Minitaur , a dog-sized quadruped bot that could cost $1,500 or less when it hits mass production. Its direct-drive electric motors both keep the cost down (since the springiness is dictated by software, not hardware) and let it pull off feats that you don't see in far pricier machines. As Ghost Minitaur can sense contact with objects through the motors themselves, it can not only climb stairs, but scale fences and even open certain kinds of doors. Shades of Jurassic Park's velociraptors , anyone?