Designer nylon bags are all the rage. Don't be fooled by the fabric, though, they'll still cost you a pretty penny. Lily Allen modeled the Chanel Cocoon Tote (price available upon request) for Fall. And now YSL came out with its own version ($995). Both are puffy, soft, and perfect for travel. They can so double as pillows at the airport. Which nylon designer bag is most Fab — Chanel or YSL?