Now that it seems that the rest of the US outside of SF and some other crunchy places has caught on to the fact that using zillions of disposable plastic bags might just not be the best idea, the next question is - what's a good reusable bag? Well, if you don't have something already that works for you, Onya Bags makes a great nylon bag (lightweight parachute fabric) that collapses into a tiny little carry pouch so you can always have it with you. The cord that secures the pouch also doubles as a should strap if you want when the bag is in use. They're a great design, definitely a step up from the random nylon bag.