I am an avid online shopper, so I have found myself spending a lot of time searching for coupons/promotions. I have come across many site, of which Ebates has proven to be the most rewarding. Ebates provides coupons for over 1500 popular sites (including walmart, target, best buy, amazon, travelocity, half.com etc...). I just came across this site so I figured I would share the knowledge.
Here is the link to Ebates (It's in "My Ebay" page b/c Ebay doesn't allow direct links in guides: --> My Ebay page for Link to Ebates