My brother is testing out a bungee-like leash on his dog. When I find out more I will post about it! :D
(fingers crossed)

made a leash
 

i lost my two dog leashes temporarily, and we made one from mule tape and a water bottle. the water bottle has a one inch diameter round handle. this was the most comfortable leash i have ever used. we made a bowline and tied this to the water bottle handle. other end a bowline that threads through the collar when u unclip the collar.

Thanks! Sounds interesting, I wish I could see a picture of it to get a better idea..