Actually, there are tons of Web sites devoted to finding these codes, which will help you save big on your next vacation. Dealhunting.com and CurrentCodes.com are two online databases that categorize thousands of coupons and secret “checkout codes.”
For example, if you are planning a Hawaiian vacation at the Marriott this spring, you can use promo code MRP to get a "Suite Deal with Daily Breakfast for Two." The offer expires May 3, 2010.
There are tons of specials to be found, so have fun looking!