I feel like I have a little bit of an advantage over everyone because I get little tips from my mom. Actually, we share this kind of information (I know where to buy just about anything at the lowest price, she always comes through with the dietary info). Anyway, in the interest of assuaging my guilt (I don't want to horde all this good info), here's a tip to all of you from my mom:

When you are buying fruits a veggies, if the PLU number begins with an 8--it is genetically engineered. If it starts with a 9--it is organic.
Cute, huh?