Celebs Give U.N. Star-Power Punch

Farrow should know. She is a longtime UNICEF Goodwill Ambassador -- she's visited Darfur eight times on her own, and she's come back with stories of the slaughter in that region.

"I was given this [necklace] by a, a woman named Halima in 2004, a refugee. And she had been wearing it when her village was attacked. And she'd been holding her, her infant son. And, Arab militia tore her baby from her arms and bayoneted him before her eyes. ….They cut them and threw them into the well. And she clasped my hand and said, 'Tell people what is happening here. Tell them we will all be slaughtered. Tell them we need help," Farrow said.

She, along with her son Ronan, wrote an op-ed in the Wall Street Journal challenging Steven Spielberg's role as an artistic advisor for the Beijing Olympics, a position he later resigned.

"What she's done is shame the Chinese government to be involved in Darfur where there is a genocide going on … The Chinese take these embarrassments quite seriously," said Andrew Cooper.

Though Farrow has, for many years, been one of the most outspoken goodwill ambassadors, she has been joined in the ranks by many more major stars, such as Nicole Kidman, Whoopi Goldberg, Susan Sarandon, Shakira, Ricky Martin, tennis player Roger Federer, French actress Catherine Deneuve and Brazilian soccer player Ronaldo.

In January the United Nations named George Clooney a Messenger of Peace after he returned from a two week trip to Chad, the Congo and Darfur. "I think what they're looking to gain from it is cameras following me to places that they're trying to get attention to and that's fine. That's a good use of celebrity if you ask me," Clooney told ABC News' Tanya Rivera after the UN ceremony.

Other U.N. Messengers of Peace include Michael Douglas, Muhammad Ali and Magic Johnson.

This past week Drew Barrymore announced a $1 million donation to the United Nations World Food Program. Barrymore has been an Ambassador Against Hunger for the U.N. since last year, but the donation is by far her largest, and she hopes will draw attention to the rising global prices for food.