I just watched the documentary Waste Land featuring Vik Muniz's project in Brazil at Jardim Gramacho.
Go watch this now! (you can get it on netflix)
I have built a very large curriculum of lessons and resources focused on recycling that hopefully one day sooner rather than later I will be able to organize and share via my blog- but for now go watch Waste Land... recyclable materials, contemporary art, portraits, oh my!
....especially if you are one of the art teachers out there enthralled in bottle-cap murals (or plastic bottle Chihuly work).
And also look into Recycled Reseen (both the DVD and the catalog) - great video to show the kids.