Okay, so this isn't a freebie. However, you can earn a % cashback for each purchase you make. I'm talking about eBates.com. The have many stores that they work with, in which most of us buy online from anyways. There is Amazon, Wal-Mart, KMart, Target, PetSmart, Best Buy, Michaels, Joann Fabrics, Groupon and Overstock.com to name a few.
If you are going to shop online, this one extra step will save you lots of money.