Designing an Electric Skateboard for a Three-legged Dog

We all love seeing a dog (or a cat) ride a skateboard, and some have become very good at it. You'll see that a dog climbs on a skateboard, and then pushes off with one back leg. Simone Giertz has a dog that cannot do that, because Scraps only has one rear leg. How can she rig up a skateboard so that Scraps can use it? Giertz wanted to make it so that Scraps could steer the contraption by balancing on her front legs, and Giertz could control the forward motion. She enlisted the help of a children's robotics club that she met while making a LEGO ad, for which she was apparently paid in LEGO blocks. (via Nag on the Lake)