Gordn Brown

British Prime Minister Gordn Brown (R) shares a joke with Tessa Jowell, Minister for the Olympics, as they attend the fourth day of the annual Labour Party Conference, in Bournemouth, in southern England, September 26, 2007. (Photo by Leon Neal/AFP/Getty Images)

Tipper Gore

Al Gore makes a funny face as he plays with Jessica Guzman, 4, after the grand opening ceremony of Echo Park, the Association to Benefit Children's new family center for homeless children, April 30, 2003 in New York City. (Photo by Stephen Chernin/Getty Images)

Silvio Berlusconi

Italian Prime Minister Silvio Berlusconi (L) jokes with Vladimir Putin during a joint press conference in Lipetsk on April 21, 2004. (Photo by Maxim Marmur/AFP/Getty Images)

Al Franken

Al Franken attends night two of the Republican National Convention August 31, 2004 at Madison Square Garden in New York City. (Photo by Justin Sullivan/Getty Images)

The Dalai Lama

The Dalai Lama (R) shares a joke with British Member of Parliament Chris Mullin during a press conference in Westminster, London, on May 21, 2008. (Photo by Kirsty Wigglesworth/AFP/Getty Images)

Rudy Giuliani

Rudy Giuliani laughs on day three of the Republican National Convention (RNC) at the Xcel Energy Center on September 3, 2008 in St. Paul, Minnesota. (Photo by Chip Somodevilla/Getty Images)

Nancy Pelosi

Rahm Emanuel (R) whispers in the ear of Nancy Pelosi during a press conference at the Capitol in Washington on October 3, 2008. (Photo by Nicholas Kamm/AFP/Getty Images)

Sarah Palin

Sarah Palin (L) shares a laughter with supporters at the end of a campaign rally at the Home Depot Center in Carson on October 4, 2008. (Photo by Jewel Samad/AFP/Getty Images)

Condoleezza Rice

Palestinian president Mahmud Abbas (R) and Condoleezza Rice (L) laugh as they walk together after their meeting in the West Bank city of Ramallah on November 7, 2008. (Photo by Tara Todras-Whitehill/AFP/Getty Images)

Barack Obama

President Barack Obama (L) and the Foreign Minister of El Salvador, Marisol Argueta, share a laugh during the first plenary session of the 5th Summit of the Americas in Port of Spain, on April 18, 2009. (Photo by Mauricio Duenas/AFP/Getty Images)

Arnold Schwarzenegger

California Gov. Arnold Schwarzenegger (C) lifts a charred dumbbell as U.S. Rep. Adam Schiff (L) (D-CA) and California State Insurance Commissioner Steve Poizner (R) look on while touring homes that were burned by the Station Fire September 3, 2009 at Vogel Flats near Tujunga, California. (Photo by Justin Sullivan/Getty Images)

Barack Obama

President Barack Obama shares a laugh with Secretary of State Hillary Clinton as he arrives to address a joint session of Congress on his embattled healthcare reform plan at the US Capitol in Washington, DC, on September 9, 2009. (Photo by Jewel Samad/AFP/Getty Images)

Bill Clinton

Former President Bill Clinton (L) laughs with actor Brad Pitt while discussing post-Katrina New Orleans at the Clinton Global Initiative (CGI) September 24, 2009 in New York City. The fifth annual meeting of the CGI gathers prominent individuals in politics, business, science, academics, religion and entertainment to discuss global issues such as climate change and peace in the Middle East. (Photo by Mario Tama/Getty Images)

Barack Obama

Rahm Emanuel makes a funny gesture ahead of the inauguration of Barack Obama as the 44th President of the United States of America on the West Front of the Capitol January 20, 2009 in Washington, DC. (Photo by Timothy A. Clary/AFP/Getty Images)

Angela Merkel

German Chancellor Angela Merkel and German Foreign Minister and vice-chancellor Guido Westerwelle share a laugh as they attend a session at the Bundestag lower house of parliament on January 19, 2010 in Berlin. (Photo by Axel Schmidt/AFP/Getty Images)

Nancy Pelosi

House Speaker Nancy Pelosi laughs during a night news conference on health care reform on Capitol Hill in Washington, March 22, 2010. (Photo by Yuri Gripas/AFP/Getty Images)

Barack Obama, Joe Biden

President Barack Obama (R) laughs alongside US Vice President Joe Biden prior to signing the healthcare insurance reform legislation during a ceremony in the East Room of the White House in Washington, DC, March 23, 2010. (Photo by Saul Loeb/AFP/Getty Images)

Hillary Clinton

This combination of photos shows Secretary of State Hillary Clinton and Pakistani Foreign Minister Makhdoom Shah Mehmood Qureshi laughing during a press briefing following their bilateral meeting at the Department of State in Washington, DC, on March 24, 2010. (Photo by Jewel Samad/AFP/Getty Images)

Sivio Berlusconi

Italian Prime Minister Sivio Berlusconi (R) laughs during a support rally for the Party of Freedom (PDL) candidate and Lazio region presidential Renata Polverinirally (L) in Rome on March 26, 2010. (Photo by Tiziana Fabi/AFP/Getty Images)

Barack Obama

President Barack Obama (R) greets the German Chancellor Angela Merkel upon his arrival for dinner during the Nuclear Security Summit at the Washington Convention Center in Washington, DC, April 12, 2010. (Photo by Jim Watson/AFP/Getty Images)

Hillary Clinton

Secretary of State Hillary Clinton and Israeli Defense Minister Ehud Barak laugh as they speak to reporters following a bilateral meeting at the State Department in Washington, DC, April 27, 2010. (Photo by Saul Loeb/AFP/Getty Images)

Timothy Geithner

Treasury Secretary Timothy Geithner (L) talks with New York Democrat Representative Charles Rangel (R) prior to an event honoring the New York Yankees as 2009 World Series champions of Major League Baseball at the White House on April 26, 2010. (Photo by Saul Loeb/AFP/Getty Images)

Silvio Berl

Italy's Prime Minister Silvio Berlusconi, President Barack Obama, France's President Nicolas Sarkozy and Canada's Prime Minister Stephen Harper laugh with other G8 leaders after posing for a group photo at the G8 Summit at the Deerhurst Resort in Huntsville, Ontario, June 25, 2010. (Photo by Jim Young/AFP/Getty Images)