I’ve been using RetailMeNot.com a lot recently to quickly find coupons and discount codes. They have the cleanest list of coupons and are free of gimmick coupons that you find on the shady coupon sites. Plus, their peer rating system makes it trivial to see if a coupon is still alive.
One really slick way to use RetailMeNot is as a keyword bookmark in Firefox. It’s by far the fastest way to figure out if a site has a useful coupon code.
To set it up, go to Bookmarks –> Organize Bookmarks…. Then click on File –> New Bookmark… and enter the following:

Now, when you want to search for a coupon, you can just use the Location bar. For example, to find Amazon.com coupons, just enter “coupon amazon”. Coupon hunting can’t get easier than that.