I'm officially sick of hearing about the "green shoots" that supposedly herald recovery in our economy. But I'm far more interested in a different sort of green that seems to be growing on Wall Street. More and more major corporations are pursuing eco-friendly initiatives that could help their image among consumers -- and their own bottom lines.

With apologies to Kermit, sometimes being green is easy
McDonald's (NYSE:MCD) recently received the platinum level of the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) award for its headquarters. Only 126 buildings in the world share the honor of this top LEED status, according to a recent BusinessWeek article.

Believe it or not, McDonald's received the award for retrofitting its 1980s-era headquarters on the shockingly low budget of just $150,000. Despite widespread belief that "greening" buildings is a pricey endeavor with a lousy return on investment, McDonald's expects the changes will recoup their own costs within a single year.

Some of the headquarters' existing design made the endeavor easy, since the campus already had several elements required for the LEED certification. Its large, forested property has two creek-fed ponds, which it uses to irrigate its landscaping and thus conserve drinking water. The company also installed light fixtures that can be dimmed on sunny days, because it has large windows that let in copious natural light.

The changes helped McDonald's cut its headquarters' electricity use by 8% last year. In addition, the company's attempts to reduce waste should help it pinch pennies. Among other efforts, it converts frying oil used in its in-house restaurant and test facilities into fuel for its shuttle-van service.

Have a Coke and a smile
Meanwhile, Coca-Cola (NYSE:KO) is launching a new plastic bottle with a twist. The PlantBottle will contain as much as 30% plant-based plastics, which come from byproducts of sugar production. It will first launch with Dasani and some other sparkling beverage brands in 2009, and with vitaminwater in 2010.

This design is more recyclable and renewable than traditional all-plastic bottles, and manufacturing for the material reduces carbon emissions by as much as 25%, compared to petroleum-based PET bottles.

Meanwhile, Wal-Mart Stores (NYSE:WMT) is continuing the green tendencies it's shown lately by giving its suppliers incentives to follow Coke's lead. Wal-Mart rates the companies from which it buys on the eco-friendliness of their packaging. The megaretailer's huge size and importance to suppliers give it considerable power to shift other companies toward less wasteful and more sustainable practices.

Innovation turns green into greenbacks
I'm particularly impressed that these changes come not from businesses that have made a name from being environmentally friendly, such as Whole Foods Market (NASDAQ:WFMI), Starbucks (NASDAQ:SBUX), and Green Mountain Coffee Roasters (NASDAQ:GMCR), but from huge, well-established companies traditionally considered resistant to change. Clearly, more companies are realizing that sustainable practices may make long-term sense for many reasons.

Green initiatives are certainly good public relations, since so many consumers are interested in being more environmentally responsible and less wasteful these days. But beyond their image-polishing potential, many of these efforts really can save money for companies over the long haul.

When companies come up with ways to do things smarter, better, and less wastefully, they'll serve shareholders well over the long term. Clever eco-friendly solutions also suggest a quality in these companies that investors should prize: the ability to stay innovative, rather than bogging down beneath layers of bureaucracy and tradition.

McDonald's, Coke, and Wal-Mart show that even venerated behemoths are pushing for better, greener practices. That's good for the environment, and good for shareholders, too.