Bono might have faced Killers and Velvet Revolvers at the Grammys -- but for his next challenge, the singer will take on Pope John Paul, former U.S. Secretary of State Colin Powell and Ukrainian president Viktor Yushchenko.

Bono is among the 166 nominees for the 2005 Nobel Peace Prize, according to Reuters. This is the second time the singer has been nominated for his philanthropic efforts, with his last nod in 2003 (see [article id="1470087"]"Norah Jones, No Doubt To Salute Bono At Tribute Dinner"[/article]). The U2 frontman has been a longtime campaigner for AIDS awareness and the elimination of Third World debt.

"We have received 166 nominations so far, of which 29 are organizations," the director of the Norwegian Nobel Institute, Geir Lundestad, said to Reuters on Thursday. "The geographical scope is wide."

Bono will also go up against the Beatles' favorite sitar player and Norah Jones' dad, Ravi Shankar, as well as organizations helping victims of the tsunami disaster (including Save the Children and Oxfam) and the International Atomic Energy Agency.

Though the list of nominees is ostensibly secret, some names were leaked to the press or made public by people eligible to nominate the individuals, which include members of the British Parliament, former Nobel laureates and selected university professors.

Last year, the Nobel Peace Prize went to an unexpected winner: Kenya's Wangari Maathai, who headed a tree-planting movement and was the first environmentalist ever to win the prize.

The official list of nominees will be announced in October and the prize will be awarded on December 10.