Pampers New Dry Max Diapers have a satisfaction Guarantee where if you are not satisfied with them for any reason, they will refund your full purchase price plus $1 for shipping. They will refund any size package, even a box of diapers. All you have to do is mail in an index card with you name and address along with your receipt and barcode off the diapers. This offer is good until 12/31/2010. You can go here to find out more details about this.
Another P&G refund currently available is for the new Pantene hair care products. If you are not satisfied with them for any reason you can get a refund of double your purchase price. This offer is available until 6/30/2011. If you would like more details, you can check it out here.