http://www.today.com/id/18530707/ns/today-money/t/sick-mailbox-full-flyers-credit-card-offers/
http://consumerist.com/2008/03/13/8-ways-to-opt-out-of-junk-mail-lists/
There is none. the USPS cannot stop mail that is destined for your address except in specific circumstances. One way is that if, in your mind, the material is "erotically arousing or sexually provocative" you can stop it with Form 1500 http://about.usps.com/forms/ps1500.pdf. Some people claim all the junk mail they get fits under this category since that is the only way to get the USPS to stop it.
sweet so i just have to say that all the junk mail i get is sexually arousing and therefore i cannot take delivery? gold!!