HURRY! This won't last long! Go here to Diet Coke's Facebook page and you'll be able to send up to 5 friends a coupon for $1/1 Diet Coke! It doesn't allow you to request one for yourself so if you want one you'll have to send one to a friend or family member willing to give it to you! (valid on 14 oz, 16 oz, and 20 oz) This should make it FREE at most stores!
Thanks Mojo Savings!