Britain's Queen Elizabeth II talks with U.S. first lady Michelle Obama and US Ambassador Louis Susman at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Dominic Lipinski, Pool)
U.S. first lady Michelle Obama and U.S. Ambassador Louis Susman arrive at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Dominic Lipinski, Pool)
US's First Lady Michelle Obama, left, and Ambassador Louis B. Susman arrive at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and governments prior to them attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Sang Tan)
U.S. first lady Michelle Obama arrives at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Sang Tan)
Britain's Prime Minister David Cameron, left, talks with Russian Prime Minister Dmitry Medvedev at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Stefan Rousseau, Pool)
Britain's Prime Minister David Cameron talks with Prime Minister of Jamaica Portia Simpson Miller and Prime Minister of Saint Lucia Kenny Anthony at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Stefan Rousseau, Pool)
Russia's Prime Minister Dmitry Medvedev arrives at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Sang Tan)
Turkish Prime Minister Recep Tayyip Erdogan and his wife Emine arrives at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Sang Tan)
President of the International Olympic Committee Jacques Rogge, left, and the Earl of Wessex attend a reception at Buckingham Palace, London, to welcome Heads of State and Heads of Government to the UK before they travel to the Olympic Stadium for the Opening Ceremony of the London 2012 Olympic Games, Friday July 27, 2012. (AP Photo / Dominic Lipinski)
Britain's Prime Minister David Cameron talks with the Prime Minister of the Palestinian Authority Salam Fayyad, center, and Tunisian President Mohamed Marzouki, right, at Buckingham Palace in London for a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Stefan Rousseau, Pool)
US first lady Michelle Obama, left, meets the Duchess of Cambridge during a reception at Buckingham Palace in London, to welcome Heads of State and Heads of Government to the UK before they travel to the Olympic Stadium for the Opening Ceremony of the London 2012 Olympic Games, Friday July 27, 2012. (AP Photo / Dominic Lipinski)
U.S. first lady Michelle Obama talks to Prince Albert of Monaco at Buckingham Palace in London at a reception hosted by Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Dominic Lipinski)
Saudi Arabia's Prince Mohammed bin Nawaf Al Saud arrives at Buckingham Palace in London for a reception hosted by Britain's Queen Elizabeth II for the heads of state and government prior to them attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo/Sang Tan)
Sir Arthur Foulkes, the Governor General of The Bahamas and his wife Joan Eleanor Foulkes, arrive at Buckingham Palace in London for a reception hosted by Britain's Queen Elizabeth II for the heads of state and government prior to attending the opening ceremony of the London 2012 Olympic Games, Friday, July 27, 2012. (AP Photo / CARL COURT)
LONDON, ENGLAND - JULY 27: Paul Kagame of Rwanda arrives for a reception at Buckingham Palace for Heads of State and Government attending the Olympics Opening Ceremony at Buckingham Palace on July 27, 2012 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - JULY 27: State Councillor Dai Bingguo of China arrives for a reception at Buckingham Palace for Heads of State and Government attending the Olympics Opening Ceremony at Buckingham Palace on July 27, 2012 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - JULY 27: President of Brazil Dilma Rousseff arrives for a reception at Buckingham Palace for Heads of State and Government attending the Olympics Opening Ceremony at Buckingham Palace on July 27, 2012 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - JULY 27: UN Secretary General Ban Ki-moon arrives for a reception at Buckingham Palace for Heads of State and Government attending the Olympics Opening Ceremony at Buckingham Palace on July 27, 2012 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - JULY 27: Culture Secretary Jeremy Hunt arrives for a reception at Buckingham Palace for Heads of State and Government attending the Olympics Opening Ceremony at Buckingham Palace on July 27, 2012 in London, England. (Photo by Chris Jackson/Getty Images)
