Have you taken the Cheerios challenge?
http://www.cheerios.com/promotions/challenge/ if you go here and sign up, they will send you emails to print coupons for cheerios. Don't forget to hit 'back" so you get them twice!

Nature Made vitamins (if you buy those - they were on sale at Walgreens last week) has codes on the sides of the package. They have a rewards program for buying thier products when you enter the codes. There are printable coupons on the site when you register as well.
http://www.naturemade.com/ try it.

By the way - Get to know your local store clerks. This last Friday I was just planning to do a stop in and out kind of thing at Walgreens. I got to talking to one of the store clerks who works there and has been seeing me frequent the store. She ended up giving me the coming week's store ad, September's Easy Saver Catalog and informed me of some special upcoming deals! I walked out of there with a bag full of samples, too.... pays to get to know the clerks!!!!

Have you tried AdPerk yet? http://www.adperk.com/
This is a site where you watch some commercials (between 10-20 commericals each lasting about a minute or two) and enter the little codes at the end. In return, you get gift cards or magazine subscriptions! I often use the time to clip coupons - kill two birds with one stone.