Ever wonder why that cereal box is only two-thirds full? Foodmakers love big boxes because they serve as billboards on store shelves. Wal-Mart has been working to change that by promising suppliers that their shelf space won't shrink even if their boxes do. As a result, some of its vendors have reengineered their packaging. General Mills' Hamburger Helper is now made with denser pasta shapes, allowing the same amount of food to fit into a 20% smaller box at the same price. The change has saved 890,000 pounds of paper fiber and eliminated 500 trucks from the road, giving General Mills a cushion to absorb some of the rising costs.

Wal-Mart has been going green, but not entirely for the reasons you might think. By sourcing more produce locally - it now sells Wisconsin-grown yellow corn in 56 stores in or near Wisconsin - it is able to cut shipping costs. "We are looking at how to reduce the number of miles our suppliers' trucks travel," says Kohn. Marc Turner, whose Bushwick Potato Co. supplies Wal-Mart stores in the Northeast, says the cost of shipping one truck of spuds from his farm in Maine to local Wal-Mart stores costs less than $1,000, compared with several thousand dollars for a big rig from Idaho.

Two paragraphs of a fine article on Wal-Mart. The profits are bad crowd should take notice that it is the profit motive that is underlies Wal-Mart's green behavior.