Struebel Line Winder. If you use loop to loop connections you can change a line over in about 2 minutes. I've even done it when a sailfish has been circling the boat, and gotten the fly back out and hooked up before it lost interest. A big upside is that the lines are storeable in quart ziplock bags, and you don't get the nasty tight little coiled memory problem after long term storage. $50 bucks, but worth every penny.