I used a wonderful handspun single-ply wool/silk - Single-Dyed Phat Silk Phat from La Lana Wools. I knit the scarf using Bryspun plastic needles.
There are more details on my blog, including more photos!
Needles to say, I'm already scheming my next project from this book :). Did you know that Melanie Falick has a gallery of "New Scarves" on her blog? All 27 scarves in a convenient layout, so we can see them side by side instead of flipping back and forth in the book!