Hotel Rooftop Pools: Maxin' Relaxin'

Once reserved for cooling towers and restaurants that spin, rooftop pools have become the social epicenter of some of America's top hotels.

City hotels, attempting to one-up one another with infinity pools and designer lounges, are turning to rooftop amenities to draw guests and local residents. What started as a novelty at New York's Hotel Gansevoort and Los Angeles's Standard Hotel Downtown has become an architectural commodity embraced by Starwood Hotels & Resorts Worldwide(HOT Quote) and Four Seasons Hotels and Resorts . Here are some of the hotels that have jump on the trend:

Plunge at Gansevoort South is Miami's top rooftop lounge.

W Atlanta - Downtown: This hotel opened less than a month ago, but has already become the it-destination in Atlanta. Located on Allen Plaza and designed by architects Pickard Chilton, the property is home to a 237-room hotel, 74 condominiums and the high-end restaurant BLT Steak. But the real action is on the roof.

The hotel's Wet lounge, on its 16th-floor roof, offers an Aegean-blue pool framed by glass walls that reveal views of the Atlanta skyline. As the sun sets, the nearby Wetbar comes to life as DJs spin house grooves into the night.

Thompson Beverly Hills, Calif.: Three rooftop pool lounges have opened in L.A. in the past year, but ABH (Above Beverly Hills) at the Thompson is the chicest. By day, starving starlets prance among rented cabanas and pint-size palm trees as uber-ripped dudes swim laps in the crystal-encrusted pool.

The pool area at this former Radisson Hotel is open to card-holding members, hotel guests and well-behaved diners. The lounge's fireplace and DJ keep the party going until midnight or 1 a.m.