I remember when we were kids, one of the things we'd love to do was take the neighborhood labrador out for a run. One of us ride on a skateboard while holding the dog's leash. The others would ride bikes, and the labrador would follow them, pulling the kid on the skateboard.

You had to start out slow, or else the lab would yank you right off the skateboard. The lab would run about as fast the other kids could peddle their bikes. The thing is that the skateboard didn't have any brakes. You had to jump off the board and run to a stop. Sometimes a pebble on the street would make the board come to a screeching halt, sending you airborne! But those were the days when it was ok for kids to get scraped up in the name of fun. Today, well...?

Anyways, that's the first thing that came to mind when I saw the "Biker Dog". It's a bracket that mounts to the rear-frame of a bicycle. Obviously, this would not lend itself to turning your dog into a alternative source of energy. But, it's a great way to ride your bike while taking the dog out for a run.