My Paper Crane has an adorable cheat sheet for which produce is best to buy organic (because they retain less or no pesticide residue) up on her page. She made a free download for it, so you can print it up yourself and keep it in your wallet for reference. I think this is a great idea because I can never remember what's on the list when I am standing in the grocery store.
Just an aside, I have been a fan of My Paper Crane's work for a long time. Check out her shop for some adorable hand-made plush and paper artwork!