what's that they used to ask at publix when bagging your groceries.....they don't ask anymore. you get the petroleum bags if you don't carry in your own. last i checked, an entry level ford mustang has over 300 horsepower, and the government gives little to no incentives to buy electric or hybrid. one could argue we had it coming.
IMO, grocery bags aren't worth worrying about. It's like doing a disk cleanup and focusing on every 1 kb file. Sure, every little bit helps but....

It's automobiles primarily.
Today's entry level Mustang does better on mpg than my '96, so I'm sure that conventional technology has helped a great deal in reducing oil consumption. But, at this point we have to ask ourselves, how quickly do we need to go from 0-60, and how much cabin space do we really need? Not only that, can't we drift over to other technologies so we don't have to pop big oil zits in our backyard and kill marine life (and people for that matter). Is that too much to ask? Hybrids could probably cut our oil consumption in half. Add in a little solar, wind, natural gas, and some nuclear. Ten years from now (if not sooner) all electric vehicles could be all the rage. But no, according to some people, we have to drill in our backyard and risk destroying our way of life just so they can make a buck, greedy batturds.