As new retirees exchange time cards for Social Se- curity checks, many also follow their dreams by flying the coop. Some head straight for laid-back country living: chopping wood, raising horses or chickens, slipping into small-town life. Others see the kaleidoscope of opportunity in city life as a retirement bonus and grab a condo or co-op in a hopping downtown metro area. Both choices have their advantages, but what you ultimately decide should reflect the future.

Want to know more before you make a move? Do you prefer an urban or rural lifestyle?Before you decide that your retirement paradise is Green Acres or Park Avenue, do a needs assessment to determine the best lifestyle for you. The benefits of city lifeAt 71, Alan Entine, a native New Yorker, has moved completely across the country to retire where Tony Bennett left his heart -- San Francisco.

A former university administrator with a doctorate in economics, Entine chose to live near his two grown daughters and their families, but the Bay City wasn't his first choice. He and his wife originally relocated to Cary, N.C., a bedroom community near Raleigh. Within six months, his wife Jan developed a serious, and ultimately fatal, illness."Thank heavens we didn't move to the coast or someplace like that," Entine says. "Because we were within driving distance of Duke (University Medical Center)."After Entine's wife passed away, he regrouped.

While Cary was nice, he gracefully acknowledged his driving days were numbered and knew he didn't want to be dependent on others for transportation. Entine decided to trade Cary for the big city.Because his daughters were there, Entine naturally gravitated toward San Francisco, which has excellent mass transit.

He rented at first, then eventually bought a small condo. He wanted a place where he could walk to stores and attractions, which his new home at the Infinity Complex, allows him to do. And, he says, the variety of residents in the area -- from young professionals to retirees -- makes life more interesting and varied than might be the case in a retirement village. Plus, there's always something going on within striking distance. "San Francisco ... has wonderful museums, theater, symphonies and opera, as well as great weather," says Entine, who hasn't abandoned academic life altogether.

He works with the FROMM Institute of Higher Learning at the University of San Francisco, which offers an eclectic cross-section of free classes for seniors. Many colleges and universities offer similar free programs.Entine also touts San Francisco's proximity to an international airport and says that although buying his condo wasn't cheap, the trade-off is that big-city living is more economical than some might think. "Sure (big cities) are expensive in terms of housing," he says, "but the day-to-day living in San Francisco isn't that much more expensive."

And there are bargains, too."On the Muni (San Francisco Municipal Rail) system, as a senior I pay $10 a month for a pass and I can have unlimited bus and train rides for a month," he says. But even if housing in San Francisco costs more than in Cary, Entine believes the convenience and variety of a big city is ultimately worth what you pay for it.

The allure of the countryBig cities don't faze Clark Pettit. From the time he was a child, Pettit lived all over the world, from Paris to Hong Kong, London to Los Angeles. When he decided to put down roots, he didn't turn to New York or Rome. Instead, he headed for the outskirts of Prescott, Ariz.Pettit, a media consultant who travels frequently in his job, is only 42 and not yet ready to give up his frequent flier account. But living where he does -- on a 10-acre horse-friendly tract -- hasn't dampened his appetite for a rural lifestyle.

In fact, he's right where he plans to stay even after he stops dashing through airports."We wanted land sufficient for horses; we wanted quiet," Pettit says.

Originally, Pettit and his wife bought land in Mexico with the intention of retiring there, but changed their minds and investigated western areas, such as California and Montana, eventually opting for Arizona. Although Prescott, located at the convergence of three cities (Prescott, Prescott Valley and Chino Valley, all in Yavapai County), is booming with retirement opportunities, Pettit and his family live in an area developed by LV Ranch Estates about 25 minutes from the nearest grocery store, 30 minutes from the nearest major medical center and 35 minutes to the center of Prescott (which is about 75 miles from Phoenix).

"We do have a small town near us called Skull Valley that has a general store, but it's not a lot closer to us -- maybe 20 minutes," he says.But while driving to the store to pick up a half-gallon of milk might be inconvenient when you settle in the boonies, Pettit points out that in many ways, living in the Los Angeles area isn't particularly more convenient. "It takes two hours to get to the airport from almost any of the outskirts of L.A., plus substantially longer if the traffic gets in the way," Pettit says. "Even a medium-sized city, which I consider Phoenix to be, isn't going to give us that quality-of-life balance."

Plus, he says, the rural lifestyle helps him keep stay fit and healthy.A 'European experience'Kyle Ezell, an urban planner and principal of Get Urban America, as well as author of "Retire Downtown," believes seniors thrive in urban settings. In fact, Ezell says all the hustle and bustle that make some people want to flee the city might be exactly what keeps them young as they age."In some ways they're like fountains of youth," Ezell says.In addition, Ezell says most retired city-dwellers can easily reduce a two-car household to one car -- or no cars at all, which frees up the cost of payments, repairs, insurance and gasoline.

And, as San Francisco's Entine points out, although mass transit isn't free, there are often deals available to older residents.Ezell says living in a metropolitan environment isn't for everyone. Some think of cities as "cold" experiences, but he says many now offer reasons for seniors to head downtown.

"The people who decide to move to their downtowns, whether it be the one closest to them or if they want to experience a life adventure and move to Manhattan, Chicago, San Francisco or some other place near their grandkids, they know what they want, and they know that city living is such an unusual choice for Americans in general that they are expecting a more European experience," he says.But Ezell doesn't believe "downtown" or "city" refers only to huge metro areas. Smaller ones qualify, too. Whether it's New York City or Prescott, metropolitan areas are gearing up to make older Americans feel welcome.