For an Annual Fee of $36, a new online service named Green Dimes offers to help us reduce our Junk Mail Intake by up to 90%. 
According to their estimates "To produce junk mail for one year, we use 100 million trees and 28 billion gallons of water".
First read about them thanks to These Can Be Yours (the consumer in you wants these products) by Good Magazine.
A good companion piece: How to deal with Information Overload…Bit Literacy
Hi Serge-
Thank you for your post about GreenDimes! We really appreciate your taking the time to tell others about our service. Make sure you check the site from time to time and see what new ideas we are working on to help make the world a better place. Take good care and thanks again for mentioning GreenDimes.
Best,
Kendra
http://www.greendimes.com
Great to see your interest in reducing junk mail! The 41 Pounds service stops your junk mail for $8.20 a year (5 years for $41) and donates more than 1/3 of the fee to the environmental or community organization you choose. They’ve raised a lot of money for organizations like StopGlobalWarming.org and Trees for the Future, while stopping junk mail. Let’s all stop the waste of trees, water, greenhouse gas emissions, and time involved in junk mail!