The American economy is addicted to waste: 43 percent of mail is junk mail, 650 water bottles are thrown out every second, and the average American uses 500 disposable plastic grocery bags a year. All of this waste, and much more, is strictly voluntary. Trash is the one big social and environmental problem every citizen can do something about. Start easy and small: get a couple of reusable shopping bags, opt out of catalogs, printed bills and other mailings you don't need, and just say no to wasteful bottled water (it's no better than tap water, and costs thousands of times more). Then build on those successes.