Because it's not like you don't have enough to carry with you, but if you're a guilt-ridden paranoid consumer like me, you might find these handy grocery wallet guides useful. (Although you could just load it up on your iPhone too.)
The fruits and veg guide lists the foods most likely and least likely to contain pesticide residue — to stretch those organic food dollars. And the fish guides are great for avoiding stocks that are over-fished or high in mercury content. Bon appetit!