Woody Allen film charms Cannes, Lady Gaga surprises

There was laughter and applause from famously fussy Cannes critics at the press screening, which opened 11 days of red carpets, media interviews, lounging on luxury yachts and late night partying in the glamorous Riviera resort.

In a testament to the festival's pulling power, Hollywood stars Robert De Niro, Uma Thurman, Salma Hayek and Antonio Banderas twirled and smiled for a legion of tuxedo-wearing photographers on the red carpet leading to the festival palace.

Hayek, in town to promote her film "Puss in Boots", held their attention for the longest with a cream-coloured floor-length dress and sideswept hairdo.

Gleaming yachts packed the harbour around the giant cinema complex, the rich and famous filled the five-star hotels and organisers hoped the 2011 festival lives up to this year's unusually high expectations.

Blockbusters "Kung Fu Panda 2" starring Angelina Jolie and "Pirates of the Caribbean: On Stranger Tides" with Johnny Depp and Penelope Cruz both launch in Cannes, as studios return en masse after avoiding the notoriously costly trip to France due to the financial crisis over the past couple of years.

And De Niro is in town as head of this year's jury. "For me to see 20 movies in this amount of time is unusual and it's kind of a bit of a vacation, because I can focus on the films, (and) don't have any distractions that I normally would have in my everyday life, so this is a terrific thing for me," he said.

Adding to the star power, pop diva Lady Gaga gave a "surprise" concert on the palm-lined waterfront wearing a two-toned hairstyle, matador-like bodice and spotted tights as fans screamed from behind the barricades.

In "Midnight in Paris", Allen, a Cannes favourite, explores the notion that bygone ages are better than the present, so Wilson's character Gil pines for 1920s Paris while painter Paul Gauguin wants to return to the Renaissance.

The 75-year-old Oscar-winning director played for laughs by transporting Wilson into a Paris populated by Hemingway, Gertrude Stein, Salvador Dali and other artistic greats.

Meanwhile, in his 21st century existence, his fiancee played by Rachel McAdams becomes exasperated by his increasingly idiosyncratic behaviour and has an affair.

"You know it's a big trap that thinking living in another time would be better," Allen told reporters.

French First Lady Carla Bruni has a cameo role as a present-day museum guide in three scenes, although she cancelled her planned appearance in Cannes because of "personal reasons", feeding rumours in the French press that she may be pregnant.

Allen said he met Bruni when he was invited to have breakfast with French President Nicolas Sarkozy and asked her on the spot to join his cast in a minor role.

"She said I would like to be in one of your movies because I would like to tell my grandchildren some day that I was in the movie," Allen said.

The darlings of Europe's festival circuit -- Pedro Almodovar, Nanni Moretti, Aki Kaurismaki, Lars Von Trier and brothers Jean-Pierre and Luc Dardenne -- are all vying for the coveted Palme d'Or prize for best picture.

So is U.S. veteran Terrence Malick, back in the limelight with only his fifth feature, the eagerly anticipated "The Tree of Life" in which Brad Pitt and Sean Penn star in a family saga set in the American Midwest during the 1950s.

Female directors feature more prominently in the main competition than in the past, although they still account for only four of 20 entries.

Belgium's Dardenne brothers have a chance to become the first directors to scoop the Palme d'Or three times with "The Kid With A Bike" and festival favourite Almodovar will aim to lift his first Golden Palm with "The Skin I Live In".