Louis Cahill at Gink and Gasoline has a qwik vid on making a double spey cast with a regular single handed fly rod. Gets you a big roll cast when you need it. Check it out > The Double Spey, For Single Hand | Fly Fishing | Gink and Gasoline | How to Fly Fish | Trout Fishing | Fly Tying | Fly Fishing Blog
yeah it is kinda fun to do when you get bored… 😉