Today is the 40th annual Earth Day celebration. Lots of things have changed in the last four decades, and with growing consumer interest in all things green, many companies have been coming up with exciting and environmentally sustainable initiatives. In some ways, such initiatives aren't just progressive, but they also represent good old-fashioned innovation.

Green changes may not only drive more sales dollars and intangible benefits like customer goodwill, but they also may enhance some companies' profitability as they cut out waste and inefficiency.

Watching for green shoots
Ever since high-profile efforts by retailers such as Wal-Mart (NYSE: WMT) to push compact fluorescent light bulbs brought green initiatives as close as your local big-box store, many companies have kept up a push to make sustainable changes.

I was fascinated last year when I read about how McDonald's (NYSE: MCD) received the platinum level of the U.S. Green Building Council's Leadership in Energy and Environment award when it retrofitted its headquarters. The coolest part: It cost only $150,000 and was expected to recoup the costs quickly through benefits such as energy savings -- a sure sign that greening up isn't always a win-lose proposition.

PepsiCo's (NYSE: PEP) Frito-Lay division landed on Fast Company's list of Most Innovative Companies in February. The division plans to have all 32 of its plants to be zero-landfill by 2011. Its innovative moves include capturing and cleaning wastewater from manufacturing so that it can be reused, and using "stack-heat recovery," in which steam from slicing and frying spuds is collected to heat wash water and warm the building in winter. And don't forget the noisy but soon-to-be fully compostable SunChips bags.

More and more companies are offering recycling solutions for consumers. Such services could create a competitive advantage for these consumer-facing companies; Target and Whole Foods Market (Nasdaq: WFMI) both recently announced new on-site recycling initiatives.

While Wal-Mart has often grappled with troubling public relations, its massive size -- not to mention its connections to consumers and product suppliers -- gives it the potential to make a powerful difference on environmental issues. It's currently working on setting up a Sustainability Index, which will survey suppliers on the eco-friendliness of their practices and educate consumers in how to best make green choices.

Dreaming of a sustainable future
A New York Times article today discussed the role of business in environmental concerns. As much as old-school, hardcore environmentalists may deride corporations' now-eager involvement in green initiatives, the truth is that corporations can and do make great headway in making things better and growing awareness among the public. But of course, we all have to be on the lookout for the dreaded greenwashing, too.

Google (Nasdaq: GOOG) and Cisco (Nasdaq: CSCO) contend that tech trends such as videoconferencing and cloud computing can reduce America's carbon footprint. The Times article also discussed PepsiCo's and Waste Management's (NYSE: WM) new Dream Machine recycling kiosks. The kiosks will be installed in high-traffic areas and aim to increase the number of recycled beverage containers from just 36% now. The kiosks seek to offer incentives for recycling by awarding points toward prizes.

In a lot of ways, environmental awareness focuses on limiting needless use of resources as well as cutting down on socially detrimental outcomes, such as pollution. There's no good reason for corporations to be at odds with such ideas. They can be better corporate citizens and even save themselves money by thinking outside the box and examining whether there are better ways to conduct their operations. Just because operational methods have always worked in the past, that doesn't mean there aren't ways to do them better and more sustainably. It just takes a little imagination.

On the first of every month, I plan on looking at interesting green innovations that publicly traded companies are trying out. I'd like to harness the collective brainpower of the Foolish community, too, and ask that folks leave comments about companies that are making interesting, innovative moves in the name of sustainability -- or not, so we can keep an eye on those, too.

It certainly can't hurt to at least try to think of ways to do things in a less wasteful manner. Waste not, want not. Happy Earth Day!

PepsiCo and Waste Management are Motley Fool Income Investor selections. Waste Management and Wal-Mart are Inside Value selections. Google is a Rule Breakers recommendation. Whole Foods Market is a Stock Advisor pick. Try any of our Foolish newsletter services free for 30 days.

Alyce Lomax owns shares of Whole Foods Market. The Fool has a disclosure policy.