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.
Some foreign policy analysts say that celebrities are far more likely to get involved in skirmishes and even ruffle some diplomatic feathers. Or, perhaps, they're also in it for the attention and up for the ground work.
Reese Witherspoon has teamed up with the UNIFEM, the United Nations Development Fund for Women, for projects that will empower women around the world. No doubt a good cause, Reese is helping the charity through her paid-role as a global ambassador for Avon, driving sales of Avon's Women's Empowerment bracelets, the proceeds of which go to Avon's Empowerment Fund, which collects money for UNIFEM.
When Farrow wrote on her website last year, "Jimmy Carter – Wake up, Jimmy! You're old enough to know better," the former president was offended. "Those are harsh words," he said in an interview with ABC News, responding to Farrow's comments about his own trip to Darfur and comments he made about a meeting with Sudanese President Oman al Bashir.
Farrow responded by saying, "I'm completely free to say anything I want. And you're right, I have no trade [LAUGHS] agreements with anyone and I can be as incautious as I, I feel the occasion calls for."
In his book "Celebrity Diplomacy," Andrew Cooper points out that Gerri "Ginger Spice" Halliwell, who was named a U.N. Goodwill Ambassador, may have had good intentions, but failed to follow through.
"The celebrities can attract attention on an issue, but they cannot solve a war. They cannot really be mediators in a crisis. There is no doubt that they have a limited role," said Montas -- a role best personified by pioneering star Audrey Hepburn who drew worldwide attention to UNICEF. Her legacy is one that today's stars hope to expand.