Whether I vacation in an urban or wilderness area, I always seem to walk enough every day to need a rest before dinner—without formally setting off to "exercise." I find it more fun to use my feet to go somewhere than to move in place on a treadmill or circle a track. What I lose in speed by dodging slippery rocks on a mountain path or pedestrians in a city, I make up in length of activity, easily forgetting the time when the surroundings are interesting.

The "walkability" of your surroundings can have an impact on your weight and activity levels. One study of nearly half a million adults in the Salt Lake City area found that a 6-foot man weighed about 10 pounds less if he lived in a walkable neighborhood. A 5-foot-5-inch woman weighed six pounds less. "Walkable" neighborhoods in that study, published in the September 2008 issue of The American Journal of Preventive Medicine, were densely populated and pedestrian-friendly, with streets in grid patterns rather than cul-de-sacs, and full of sidewalks and useful destinations: shops, parks, libraries, and restaurants.