Jeny's Surprisingly Stretchy Bind-Off technique. I recommend you watch a tutorial before trying this one. It isn't difficult, I think you should practice before you start mucking about with live stitches. I know I'm glad I watched it a couple times.
Pattern: River Run Shawl (available on Ravelry)
Yarn: Biggie from Dancing Leaf Farm and Wool of the Andes - Superwash from Knit Picks