Re: Furl Girl Leaders
As Mojo said, furled leaders have been around for a looooong time. Had you bumped into Isaak Walton or Charles Cotton back in the 1600's, they could have shown you the furled leader they were using.
If you are interested in the history of various flyfishing concepts, try to find a copy of a book by Darrel Martin called "The Fly-Fisher's Craft". Darrel may be most responsible for reviving the interest in Furled Leaders, his book "Micropatterns" is one of the first detailed references I recall seeing.