A website affiliated with Fast Company and called FastCo.Exist has some interesting information on sustainability.
Consider the article showing how Mexico City is promoting several public goods simultaneously. The city’s environmental agency recently launched Mercado de Trueque, a barter market where recyclable materials are exchanged for fresh food to support the city’s farmlands.
Michael Coren reports: ” ‘This innovative program is designed to show citizens directly and tangibly how what we call trash becomes raw materials. If solid waste is properly separated, it still has value,’ writes the Ministry of Environment (in Spanish). The market accepts glass, paper and cardboard, aluminum beverage cans, PET plastic bottles, and returns ‘green points’ redeemable for agricultural products grown in and around Mexico City, including lettuce, prickly pears, spinach, tomatoes, plants, and flowers.” More here.
Co.Exist also has an article by Ariel Schwartz on how you may track where the things you buy come from. For example, your canned tuna. Check it out.
Suzanne's Mom's Blog 
This was the story I was searching back to find! I was fascinated. What a wonderful thing.
And the supply-chain thing is fascinating as well–must go visit the site and look at more of the supply chains.
It makes such sense — both for waste reduction and for farmers. Not to mention the consumer!