Take a deep breath, everyone ... it's time to slow down.

That is, if after running full speed all year checking off unrelenting to-do lists at work and at home, you haven't forgotten how to brake for a summer break. Not only do U.S. workers receive fewer paid vacation days than Europeans (an average of 8.9 days after one year vs. a minimum of 20 to 25 in the European Union). One third of employed Americans don't even take all the vacation days they're entitled to, a new survey has found. Americans typically leave four days unused--up from three in last year's "Vacation Deprivation" survey, conducted by Harris Interactive for online travel company Expedia.com.And when Americans do take time off, about 1 in 4 still checks in on work via E-mail or voice mail.

With that kind of seepage, no wonder vacation itineraries begin to resemble work agendas, with every minute made to COUNT, as you CRAM in as much FUN as possible. But wait (yes, you heard me, WAIT): Don't those STRESS-inducing CAPITAL LETTERS spell just the opposite of TIME OFF?

Alas, in our productivity-driven society, we too easily forget that "vacation isn't about output," like a job, says Joe Robinson, a work-life consultant and author of Work to Live. It's about play (in lower-case letters) and about leaving time for serendipity.

It's also about health: At least two studies have correlated the stress-reducing benefits of annual vacations with lower rates of coronary heart disease. "Our bodies are designed to be used and to recover; that is basic biology," points out Wolfgang Linden, psychology professor at the University of British Columbia. "You need a reprieve."

Backyard breaks. And though wanderlust may take you on a vacation around the world, your own backyard can provide that respite. The city of Vancouver, Canada, for instance, where Linden lives, all but encourages citizens and visitors to take breaks. Buses sport bicycle racks; resplendently green Stanley Park beckons strollers as well as in-line skaters; mountains on one side and water on the other can spur the urge for adventure as much as inviting dreamy rumination and a restful letting go.

Which brings us back to going slow. "There's a taboo against slow, that it's a four-letter word. As opposed to busy, which is a badge of honor," says Carl Honore, author of In Praise of Slowness: Challenging the Cult of Speed. But what Honore calls the "slow ethos" does not mean moving at a snail's pace. Rather, it's "doing things as well as possible instead of as fast as possible." It's no good trying to "slow down at a fast pace"--spending a spa day jumping from yoga class to a massage to a facial to meditation lesson to a speed walk, then heading to the airport for a flight spent furiously catching up on your laptop. Not just on vacation but in life in general, he asserts, "we don't get the full pleasure because we don't take time in between activities to decompress, to reflect on and enjoy what we do."