Richard Harris could have left his cake out in the rain with one of these.

Walmart execs recently examined a water-resistant, biodegradeable cardboard boxes from Interstate Container, according to The London Times. The boxes stay waterproof for two weeks. Thus, Walmart employees could fill them with old bits of paper and lettuce scraps and then truck them off to the dump before the boxes lose their shape and the green icing flows away.

The idea is to eliminate waste as much as possible. From the article:

"By 2025 it wants to eliminate all waste by reducing, recycling or reusing everything that comes into its 4,100 American stores. For Asda, its British operation, the target is 2010."

Since 2005, Walmart has been aggressive in adopting and/or testing green technologies. It has put LEDs in its freezer cases and examined ways to use more natural lighting for stores. Removing lights in coke machines in break rooms saved $1 million a year. A couple of stores have served as beta sites for solar panels.

In 2008, it began to tell its suppliers to reduce the energy consumption of the products that would end up on Walmart shelves by 25 percent by the end of 2010.