In the spirit of New Year's resolutions, I just read a list of tips for responsible travel. That's eco- and culturally responsible travel, not forgot-my-passport and left-my-suitcase-in-a-taxi responsible.
Suggestions include ways to cut down on flights and to make the flights you do take more efficient (it's good to know that cutting out as many stopovers as possible not only makes for a more pleasant journey but reduces emissions). Tips go beyond just transportation though, to ideas such as hiring local guides and eating local foods over imported items.
In the last year, I've had the chance to visit more places with local guides, and I'm a total convert now. Trained and certified guides seem to know just about everything about a place, not only what's right in front of you at any given moment but history, culture, geography, flora and fauna, and seemingly everything else. At least in my experience, guides are full of anecdotes that illustrate various facets of local life, and also know the good places to get local food.