Do you still use plastic bags? If not, chances are you're carrying around a reusable bag for groceries... and like any other good deed, this one's not going unpunished either. So a little heads up: you may want to make sure you're regularly washing your reusables, because it's now been found that they're most likely carrying around large amounts of bacteria!
More specifically, "coliform bacteria, suggesting raw-meat or uncooked-food contamination, was in half of the bags, and E. coli was found in 12 percent of the bags" tested in a recent study. While washing bags reduced levels to practically nothing, the study also found that people rarely, if ever, are actually washing them. So for those who waited in line for the "I'm Not A Plastic Bag" at Whole Foods... that's like three full years of bacteria by now!
So, one more thing to toss in the laundry (just make sure you buy ones that are washable: polypropolene, cloth or canvas).