For example, more and more travel-related companies are working on the so-called "greening of the supply chain, making sure that the products they buy are produced in sustainable ways. Many are reaching beyond their own walls when it comes to CSR. And more and more are asking their guests to support their programs.

For instance, Marriot International. Marriot won a World Savers Award last year, and have they ever accelerated their efforts in these areas. Bill Hartwig, who is the head of Global Procurement at Marriott International, told us recently that he has been spending a lot of his time thinking about—of all things—hangers. They've identified an environmentally progressive factory in China and are working with it to see if it might be able to manufacture hangers that meet Marriott's sustainability standards. Marriott has recently also just made a $2-million-investment in saving 1.5 million acres of rainforest in Brazil as a way to offset its carbon footprint.

Banyan Tree, the Asian luxury chain, supports various community projects outside of its hotels and asks guests to contribute $2 for every guest night, which the company matches.

Tensie Whelan, Executive Director of the Rainforest Alliance, will be speaking on our panel about consumer behavior this morning. She's been working with a number of hotel companies to persuade them to serve only Rainforest Alliance-certified coffee, coffee that's been grown in environmentally sustainable ways, and she's finding lots of takers. Holiday Inn has just signed up, as did Hyatt Hotels, Marriot Renaissance, and JW Marriott—and there are other major hotel chains in the pipelines.

All these supply chain initiatives, of course, have a great impact, all the way down the chain. David Jerome of Intercontinental Hotels, unfortunately couldn't be here this morning, but he told us recently that they have come to a tipping point on this.

For example, IHG is increasingly focused on issues like how to make sure that the furniture the hotels buy is made from sustainable materials, including sustainably logged wood. (Renewability and recyclability are words he throws around a lot.) He also said that one of the factors leading them down this path is their customers' growing interest in these issues.

Any single one of these initiatives, of course, does not a green hotel make. But as Jerome said, "If we can get the needle to move even slightly, we can have a huge impact.

Here's to moving that needle. And to the power of travel to do so.