Editor's note: Watch Live: Webcast of Peace Prize announcement at 5 a.m. ET
(CNN) -- The winner of the Nobel Peace Prize will be announced Friday morning in Oslo, Norway.
A record number of nominations -- 241 -- were received by the Nobel committee this year. Of those, 53 are organizations, including WikiLeaks -- the website founded by Julian Assange that facilitates the publication of classified information. It made headlines for leaking documents and videos related to the wars in Iraq and Afghanistan and also released thousands of U.S. diplomatic cables.
Among the individuals thought to be strong contenders are several involved in fomenting peaceful uprisings in the Arab world.
They include Wael Ghonim, the former Google executive who used social media to jump-start social change in Egypt, Tunisian blogger Lina Ben Mhenni, who criticized the regime long before the uprisings began, dispersing information to the outside world, and Israa Abdel Fattah, who helped organize Egypt's online April 6 Youth Movement in 2008 and played a role again in 2011.
Other favorites are Sima Samar, head of the Afghan Independent Human Rights Commission and a trailblazer for women's rights in Afghanistan, German Chancellor Helmut Kohl, Cuban dissident Oswaldo Payas Sardinas and Ghazi bin Muhammad, a Jordanian advocate of interfaith dialogue.
Another organization which could be in with a shot is Memorial, a Russian civil rights group known for its fight for to protect refugees and victims of political persecution and human rights violations in war zones.
Apart from the winner, the names of the nominees cannot be revealed by the Nobel committee for another 50 years.
Last year, Chinese dissident Liu Xiaobo won the prize but could not attend the award ceremony. The political activist and longtime critic of communist rule in China is serving an 11-year prison term for what the Chinese government calls "inciting subversion of state power."
U.S. President Barack Obama won for what the committee called "his extraordinary efforts to strengthen international diplomacy and cooperation between peoples" in 2009.
Nobel prizes in literature, chemistry, physics and physiology or medicine were awarded earlier this week.
Swedish poet Tomas Transtromer won the Nobel Prize in literature on Thursday. The Swedish academy said it gave the award to Transtromer "because, through his condensed, translucent images, he gives us fresh access to reality."
On Wednesday, the prize in chemistry was awarded to Israeli scientist Daniel Shechtman.
Shechtman is a professor at the Technion-Israel Institute of Technology and is known for his discovery of quasicrystals.
On Tuesday, the Royal Swedish Academy of Sciences named Saul Perlmutter from Lawrence Berkeley National Laboratory and the University of California, Berkeley; Brian P. Schmidt of Australian National University and Adam G. Riess of Johns Hopkins University and the Space Telescope Science Institute the winners of the 2011 Nobel Prize in physics. They made the discovery that our universe apparently is expanding at an accelerating rate some 14 billion years after the Big Bang.
The Nobel committee on Monday named Ralph Steinman, a biologist with Rockefeller University, and scientists Bruce A. Beutler and Jules A. Hoffmann, the winners of the 2011 Nobel Prize in physiology or medicine.
The Nobel Peace Prize has been awarded 91 times since 1901.
The youngest Nobel Peace Prize laureate is Mairead Corrigan, who was 32 years old when she was awarded the Peace Prize in 1976. The oldest winner is Joseph Rotblat, who was age 87 when he was awarded the Prize in 1995.
The Nobel Peace Prize is awarded by a committee of five people chosen by Norway's parliament and is named for Alfred Nobel, a Swedish scientist and inventor of dynamite.
Nominations come from lawmakers around the world, university professors, previous Nobel laureates and members of the Nobel committee.