U.S. model Lydia Hearst poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Czech model Karolina Kurkova poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

South Sudanese model Alek Wek poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

German model Eva Padberg poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

U.S. model Lydia Hearst poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Czech model Karolina Kurkova poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

U.S. actress Milla Jovovich appears on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT) 

A model wears a creation of Agent Provocateur on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

U.S. model Lydia Hearst wears a creation of Agent Provocateur on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

Model Naomi Campbell presents a creation from John Galiano on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: FASHION ENTERTAINMENT SOCIETY) 

A model performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

A model performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Models present creations by French designer Jean Paul Gaultier on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION ENTERTAINMENT) 

Models perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

French model Baptiste Giabiconi performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

A model performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

U.S. actress Milla Jovovich performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT SOCIETY) 

Model Naomi Campbell (R) and Spanish actor Antonio Banderas arrive on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (ENTERTAINMENT) 

Spanish actor Antonio Banderas (L) and British model Naomi Campbell perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

U.S. actress Milla Jovovich performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT SOCIETY) 

Spanish actor Antonio Banderas (L) and British model Naomi Campbell perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

Actress Milla Jovovich (C) performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

Drummers perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

Models perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Visitors kiss during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

A model walks on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

Models perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Austrian actor Nicholas Ofczarek performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

A model performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

Danish actress Brigitte Nielsen poses during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT FASHION SOCIETY) 

A model performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: FASHION SOCIETY) 

Dancers perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

A model wears a Philip Treacy creation during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

A model wears a creation of Agent Provocateur on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

A model wears a Philip Treacy creation during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

A model wears a Philip Treacy creation during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

A model wears a Philip Treacy creation during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY FASHION) 

Models Naomi Campbell (L) and Karolina Kurkova walk on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (ENTERTAINMENT) 

Models perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (ENTERTAINMENT) 

Actors perform on stage during the opening ceremony of the 20th Life Ballin Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

Austrian actor Nicholas Ofczarek performs on stage during the opening ceremony of the 20th Life Ballin Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

U.S. singer Jon Secada performs on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

U.S. actor Sean Penn (L) and former U.S. president Bill Clinton watch the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

U.S. actor Sean Penn (L) and former U.S. president Bill Clinton watch the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

U.S. actor Sean Penn (L) and former U.S. president Bill Clinton watch the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: ENTERTAINMENT POLITICS SOCIETY) 

A visitor takes a photo during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY FASHION) 

A participant arrives for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

A view of the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY ENTERTAINMENT) 

Actors perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

Dancers perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENTERTAINMENT SOCIETY) 

Actors perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

Actors perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

Dancers perform on stage during the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's City Hall. REUTERS/Lisi Niesner (VIENNA- Tags: ENTERTAINMENT) 

German TV presenter Sonya Krause (L) arrives for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

A participant arrives for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

Participants arrive for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

A participant arrives for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SOCIETY) 

Participants arrive for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY) 

Participants arrive for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY TPX IMAGES OF THE DAY) 

A participant arrives for the opening ceremony of the 20th Life Ball in Vienna May 19, 2012. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. REUTERS/Lisi Niesner (AUSTRIA - Tags: SOCIETY)