This week there are a few Register Rewards promotions at Walgreens. Since it's tricky to roll rewards, here's a reminder: If you are using a Register Reward, you cannot use a manufacturer coupon on a filler item. The number of manufacturer coupons and Register Rewards used as payment must be equal to or less than the number of items purchased. To read about how to shop at Walgreens, click here. Then click on the "Walgreens 101″ tab. Click here for the skinny on the new Balance Rewards Program.