Barack Obama is the 44th and current president of the United States, and the first African American to serve as U.S. president. First elected to the presidency in 2008, he won a second term in 2012.

Swimmer Michael Phelps has set the record for winning the most medals, 22, of any Olympic athlete in history.

Lance Armstrong is a professional American cyclist and testicular cancer survivor who, in 2012, was stripped of the seven Tour de France titles he won from 1999 to 2005 due to evidence of performance-enhancing drug use.

Whitney Houston was an American singer and actress whose first four albums, released between 1985 and 1992, amassed global sales in excess of 86 million copies.

A-list actor and Scientologist Tom Cruise is the star of many box office hits, including Risky Business, A Few Good Men, The Firm, and Jerry Maguire.

Actress Katie Holmes played Joey Potter on The WB teen drama Dawson's Creek from 1998 to 2003. She has a daughter with actor Tom Cruise.

U.S. Army General David Petraeus became director of the CIA in 2011. He resigned from the post in 2012, after his extramarital affair with Paula Broadwell was publicized.

Kate Middleton, Her Royal Highness the Duchess of Cambridge, married Prince William in 2011 at Westminster Abbey. She will not be a princess until Prince Charles inherits the throne.

John Glenn was the first U.S. astronaut to orbit Earth, completing three orbits in 1962. He has also served as an Ohio senator.