These photo collages by Chris Jordan are amazing. It is some of the most powerful art I have ever seen.

This is a 5 by 10 foot piece depicting 2 million plastic bottles, the number used by Americans every 5 minutes:
detail:

Here’s an excerpt from one his Artist’s Statements:

The pervasiveness of our consumerism holds a seductive kind of mob mentality. Collectively we are committing a vast and unsustainable act of taking, but we each are anonymous and no one is in charge or accountable for the consequences. I fear that in this process we are doing irreparable harm to our planet and to our individual spirits.

As an American consumer myself, I am in no position to finger wag; but I do know that when we reflect on a difficult question in the absence of an answer, our attention can turn inward, and in that space may exist the possibility of some evolution of thought or action. So my hope is that these photographs can serve as portals to a kind of cultural self-inquiry. It may not be the most comfortable terrain, but I have heard it said that in risking self-awareness, at least we know that we are awake…

Lots more at http://www.chrisjordan.com/

These are pieces that I would love to see in person. I would like to know more about his techniques as well; this process must be incredibly painstaking.