Reusuable bags for shopping has become pretty mainstream. Most grocery stores sell their own and places like Whole Foods gives a little refund for every bag you bring in. We use these great Chico Bags, which my husband got a few years ago on a trip to San Francisco. I love them because they are stuffed into a little pouch that is part of the bag. So it's easy to keep in your purse or glove compartment, and they're only $5! They've also have another line called the rePETe which is made from 99% recycled content such as plastic bottles.