Seeing people walk their dogs you often see them struggling against the leash. What about a wireless leash. Would come in two parts. A transmitter that you carry with you and a collar that has a receiver in it that the dog wears. The "leash" would have two thresholds that could be set. If the dog gets far enough away from the owner that they cross the first threshold a beep would sound to let them know to slow down. If they keep going, they get a zap. Would work a lot like the invisible fences that are out. There could also be a recall button that would send a different beep that lets the dog know to come back to the owner. And an emergency zap that could be triggered if necessary. For example, if another person or dog is within the leash threshhold and you need to bring the dog back to you quickly.