Agree with Zoe's headline - Wal-Mart's sentiment is nice, I suppose. But there's no real incentive for customers to ditch the plastic bags, particularly when WM employees hand them out like candy. (Seriously, I'm always in shock at the amount of bags they use! Double bagging a box of cereal to take it, in your cart, to your SUV? Really?). The only way to convince those customers (including the ones who don't really care about greenhouse gas emissions) to make the switch, is to charge them for the plastic bags like they do in Europe. The psychology of saving even $0.05 is a lot more effective than making customers feel good about saving the planet.