I came across a good post that discusses a few places you can go to find the information for stopping junk mail. It mentions ForestEthics, OptOutPreScreen (two thumbs up by Federal Trade Commission), and MyJunkTree.
Usually, to stop companies from mailing you junk catalogs and mail, you’d have to do the research and write them opt-out letters. In addition, these requests must be renewed/refiled once every 5 years. The federal law allows companies to start mailing you again after 5 years is up.
When you think about the time involved, the stamps you need to lick, and the letters you must write and deliver, you might find that using one of those paid services is not so bad after all. MyJunkTree offers a 3 year subscription for $20 (is that per year or per 3 years?).
With an online postal mailbox and paperless billing, my belief is that your normal mail and junk mail will be reduced by 90% or more. However, your primary residence still receives mail right? Services like MyJunkTree will likely help you out on this front.

September 3, 2008 at 2:22 am
I happen to be one of the owners of MyJunkTree and as a new company I search the web to see if we are getting any visibility out there and I post on relative blogs.
We launched the company because we were tired of all the junk mail we were receiving and we personally did not want to bounce all over the web to contact all the different companies to stop it all. First and foremost we wanted to let people choose what they wanted to let come to their home knowing that some people really do like some of the coupons and catalogs. So our clients choose what they want stopped.
We also had to provide a service that is different than the other services out there, so here is what we offer:
1. We have a database of over 1300 catalogs that you can choose to stop.
2. We have over a 2000 charities/Non-Profits that you can stop solicitations from.
3. Stop the delivery of the national phone directories.
4. Stop the delivery of the weekly coupons.
5. Stop the general credit card offers as well as the ones from your own major bank.
6. Stop the miscellaneous junk mail from the data brokers.
7. You can register on the National Do Not Call Registry from the website.
8. You can order your no strings attached free annual credit report right from the website.
9. We plant trees with every new membership.
And, yes we are a paid service and yes you can do everything that we do for free, if you want to do all the research and spend the time contacting the companies yourself it can easily be done. We have just done all of the legwork for our clients and feel there is value in the service we provide.