To encourage carpooling, the company partnered with Atlanta's Clean Air Campaign, which enters carpoolers into monthly drawings for gift cards. It also designated preferential parking closest to the building for carpool and hybrid vehicles. Neither of these programs cost anything to implement.

The company, however, does offer an incentive program of up to $4,000 to help employees purchase hybrid vehicles.

"There's no direct payback for this program but it demonstrates our commitment to the employees and the environment," Linstroth says. "It's our way of rewarding people for changing their commuting behavior."

Turn Waste into Profit

When you think about the waste your company produces, look beyond conventional recycling as a means to an end, suggests Bill Hoffman, of the Waste to Profit Network. Waste to Profit is a Chicago-based waste synergy network that matches companies that have or need raw materials to share that would otherwise be thrown away.

"We bring people together from different industries who wouldn't normally talk to each other and we get them talking about how they can work together," he says.

Through community meetings and a network database, companies develop partnerships to share and repurpose their waste. For example, a snowplow manufacturer uses old rubber tires to make parts for its snowplow blades. There's also a countertop manufacturer who uses difficult-to-recycle waste from a specialty coated glass manufacturer for a custom line of countertops.

Shawn Kingzette, a certified arborist at Care for Trees in Chicago, made a similar connection after seeing his customers' reactions after cutting down their trees because of disease or storm damage.

"Trees are important to people and they are often sad to lose them," he says. Instead of tossing the dead trees into a chipper, he sends them to a local miller who either uses them to make furniture, or cuts and returns the wood to the original owner, for a price, so they can hang on to the memories -- and the carbon -- that are locked into the wood.

"The broader lesson in this is to analyze your waste and determine if there is a better use for it," Kingzette says.

When he cuts down trees that don't have sentimental value, he converts them to wood chips that he can sell for landscaping, which retains the carbon in the material for several more years.

"It makes good business sense for me, and as long as the material stays in wood form, that carbon is trapped," he says.

Get Everyone Involved

All the experts agree that employee involvement is critical to making any long-term green initiative a success. The best way to do that is to make it fun, says Christina Page, director of climate and energy at Yahoo.

The company began trying to make green initiatives fun on Earth Day in 2007, when the Yahoo challenged employees to reduce their energy consumption 20 percent within a week. The incentive?