Earth Day 2010 has come and gone, but many companies are still pursuing new environmentally sustainable initiatives. Let's look at some interesting recent green developments that might merit investors' attention.

Waste not, want not
Green Mountain Coffee Roasters (Nasdaq: GMCR) and International Paper (NYSE: IP) have finally found the perfect eco-friendly lid for eco-friendly cup they launched in 2006. The Ecotainer's new lid is made of renewable polylactic acid, and it's the only compostable hot cup lid being made in the U.S.

This green development may put Green Mountain's coffee rival Starbucks (Nasdaq: SBUX) at a disadvantage in its own quest for an eco-friendly image. After 11% of its shareholders voted for a proposal encouraging the company to recycle more, Starbucks held a "cup summit" in Boston last month. The java giant met with recyclers, manufacturers, and non-governmental organizations about ways to make its disposable cups easier to recycle. Starbucks can at least take comfort in knowing that nobody's perfect; Green Mountain's popular Keurig K-Cups are not recyclable.

A sustainability giant
Wal-Mart (NYSE: WMT) could play a big role in helping Earth-friendly start-ups survive. The Wall Street Journal reported that Terracycle, a small, private company that fashions products out of difficult-to-recycle packaging, is hoping that large retailers like Wal-Mart will take up its cause more consistently -- and help the tiny company finally turn a profit.

Wal-Mart carried Terracycle's wares during a promotion for last month's Earth Day. In one clever touch, the retailer stocked Terracycle's backpacks, crafted from Kraft's Capri-Sun packages, next to the actual Capri-Sun beverages.

While Wal-Mart apparently told Terracycle that its sales did justify carrying the smaller company's products again next Earth Day, a more consistent relationship with the Bentonville behemoth, or other large retailers like Target, would surely help Terracycle' products reach a wider audience. The company has amassed warehouses of materials as it awaits increased demand.

Wal-Mart's huge customer base and influence can wield tremendous influence, good or bad, over suppliers' green initiatives. In addition, stores that purchase and promote more environmentally friendly goods could help encourage shoppers to think green more often -- and foster greater goodwill among eco-savvy shoppers.

Green power to the people
On the renewable energy front, the Environmental Protection Agency released its list of top green power purchasers. Among Fortune 500 companies, Intel (Nasdaq: INTC) was No. 1, purchasing more than 1.4 billion kilowatt hours per year and deriving 51% of its energy needs from renewable energy. Kohl's (NYSE: KSS), Whole Foods Market (Nasdaq: WFMI), Dell, and Johnson & Johnson round out the top five.

Sustainable initiatives not only make the world a cleaner, less wasteful place, but often help companies drive additional revenues, save money, or devise better operational processes. Given consumers' growing interest in sustainable living, companies that source their power or otherwise conduct business in eco-friendly ways could enjoy a significant boost to their public image. In the long run, that could benefit their shareholders as well.

Have you noticed any interesting green innovations among publicly traded companies recently? Want to call a company out for lame, half-hearted efforts to "greenwash" its image? Sound off in the comments boxes below.