At 5 a.m. the sun was soon to be rising over the fabled canals of Venice, but Catherine Zeta-Jones wasn't done with the night before. Sitting down at a piano in the bar of the Hotel Cipriani, the actress—in town to promote her latest movie, Intolerable Cruelty, at the city's annual film festival in September—used the pipes she displayed to Oscar-winning effect in Chicago for an impromptu concert of Welsh folk songs. "George Clooney, who was sitting with Sean Penn, was humming along," said one onlooker. "It was really cool."

She has every reason to be singing a happy tune. Last April, Zeta-Jones, 34, husband Michael Douglas, 59, and son Dylan, 3, welcomed a new baby, Carys, into the fold. Now, after taking time off for the birth, Zeta-Jones is back onscreen this week as a sultry gold digger in Cruelty, opposite Clooney's aggressively amorous divorce lawyer. And that thud you heard at the film's premieres in Venice and Beverly Hills? The sound of jaws dropping. After gaining weight while pregnant, Zeta-Jones has made a triumphant return to her old voluptuous self, topping it off with a sleek new hairstyle with bangs that's winning raves from her husband. "Michael loves it," says a pal. "He thinks she looks 16 years old."

How did she get that lean, fresh, just-back-from-vacation look? Because she has been following a regimen of sensible diet and exercise (see box), and because she's, well, just back from vacation—a summer European idyll that included a visit to the Lake Como, Italy, villa belonging to new pal Clooney, who considers his costar a triple threat: "beautiful, smart and funny."

While filming Cruelty in Vegas last year, both stars indulged their taste for the tables: "George has the 'cooler effect,' " says costar Paul Adelstein of Clooney's bad luck. "Catherine, on the other hand, made some money gambling." Though Zeta-Jones's immediate plans include spending time at her family's estate in Bermuda and shooting Steven Spielberg's romantic drama Terminal (costarring Tom Hanks), the star just may be planning to take her new dancer's physique—and her earthy sense of humor—back to Sin City. "I have a real ambition to do a really tacky Vegas show," she says. "With drag queens."

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Body After Baby
How did Catherine Zeta-Jones lose the baby weight since the April birth of daughter Carys? "Contrary to what everyone wants to say, it's not the south Beach Diet or the Zone diet or Atkins," says a source close to the famously curvy star. "She eats what she wants, but it's very balanced: Protein, a few carbs, lots of vegetables, no fried foods, and she's constantly drinking water. She's not somebody who obsesses about it." The glamor goddess is, however, someone who knows that to get back into he old jeans you gotta move it to lose it. Besides "chasing [3-years-old son] Dylan around," says the source, Zeta-Jones works out four of five times a week. "When she's in Bermuda, I'll call and she'll say, 'Oh, I just came in from a long swim.' She loves to go for really long walk. Otherwise it's the treadmill."

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