Where oh where can the international glamour-puss find a home? Making a beeline up the bodacious South American coast, Julia Chaplin reports that the beaches of Brazil and Uruguay are hot, hot, hot

Late afternoon is when the action kicks in at La Huella, a rustic-chic café overlooking the main beach in José Ignacio, a fishing community turned sophisticated resort on a bit of land jutting into the Atlantic Ocean, twenty-six miles up a wide-open road from Punta del Este, Uruguay. It's here that I meet Wally and Facu, two PR agents/party promoters from Buenos Aires who seem to be running the show from their sun chairs and an arsenal of BlackBerrys and cell phones. Jet-setters too busy to plan rely on plugged-in PR people to give them an insider's social agenda the instant they touch down in a new place. Friends can be flaky and turn off their cell phones, but not PR people, who share a symbiotic interest in getting the glamorous to nightspots and events. Wally and Facu both have perfect Afros, retro-'70s bathing trunks, and mirrored aviator sunglasses. They compliment me on mine (they're from A.P.C.), and we bond instantly. "Mario is coming next week," Facu tells me. (As in Mario Testino, the Peruvian-born fashion photographer known for catapulting South American models to stardom.) "Gisele is here," he continues. "Naomi, too. She's with Custo Barcelona." (As in the Spanish designers.)

Facu sifts through his pockets, pulling out stacks of thick, expensively wrapped invitations, takes my notepad, and jots down a fail-safe party itinerary that will carry me through the next ten hours: Cream, an open-air bar where the hipsters ritualistically flock on chill-out mats to watch the sunset, followed by a cocktail party for an Argentine interior design magazine at Unlounge, then a late dinner at the Mercedes-Benz showroom/restaurant and a few house parties afterward. I take a swim in the chilly ocean and stroll on the windswept beach, losing myself in its rocky coves and pastel sand dunes—until I notice that several of the sunbathers are actually paparazzi toting large cameras with telescopic lenses. It sums up the mood of José Ignacio perfectly.

I've come to this sunny corner of the world because I have long been fascinated by the idea of the South American jet-set. Think Audrey Hepburn's tuxedoed suitor in Breakfast at Tiffany's, or such quintessential playboys of the 1950s and '60s as Francisco Pignatari (heir to a mining fortune, he ran off with Princess Ira von Fürstenberg) and Jorge "Little George" Guinle (who famously romanced Marilyn Monroe and Jayne Mansfield and whose family, the richest in Brazil at the time, owned Rio's Copacabana Palace hotel). And while Italy's playboys seem to have been phased out with the lira, South America's—judging by the stories I'd heard—are still champions of unabashed race car–driving and polo-playing flash.

Much like fashion, destinations go in and out of style among the international crowd. The trends make the rounds at cocktail parties and late-night dinners like hot insider stock tips. This year the whispered word was, "Cancel in St. Barts and St-Tropez and head south"—specifically to a handful of tony beach locales in Brazil and Uruguay. Brazil, isolated by twenty years of military dictatorship and then by a decade of economic woe, is having a cultural moment not seen since the sixties: Witness the phenomenon known as Gisele and the planeloads of other exotic-looking models being exported to fashion capitals' runways. A talented new generation—including fashion designers (Alexander Herchcovitch, Isabela Capeto, Carlos Miele), architects (Isay Weinfeld), and film directors (The Motorcycle Diaries'; Walter Salles, City of God's Fernando Meirelles)—is updating the country's image from the era of Oscar Niemeyer and bossa nova.