Movie stars, models and musicians can often command the media's attention when they promote charitable or environmental causes. Angelina Jolie, Bono, Leonardo Di Caprio are just some of the A-list celebrities lending their famous faces to humanitarian issues, third world debt and climate change.
For many years, singers and song-writers have come together to draw the world's attention to famine and poverty in Africa.
The famous 1985 song 'We Are The World' was a number one hit - but it also contributed to a debate about the role of celebrity-humanitarians and whether the money they raised reached those who needed it most.
Celebrities help humanize issue
Peter Kessler of the United Nations High Commissioner for Refugees says so-called celebrity diplomats help to humanize an issue, and to reach people when political campaigns often fail to do so.
"As we saw with Princess Diana when she first held the hand of an AIDS victim, it's spreading that message that these people are safe," Kessler said. "They're not a threat. They're threatened. And you can also reach out to them in your own way. You don't have to be a VIP celebrity."
Di Caprio's focus: climate change
Actor Leonardo di Caprio's cause of choice is climate change. His documentary, The 11th Hour, gave him what he says he was searching for: the opportunity to gain a sense of purpose.
"And you know, for me, watching the cultural understanding of the issue now is, in itself, encouraging," di Caprio said.
Baroness Caroline Cox, a member of the House of Lords, is one of Britain's prominent humanitarians. She has spent decades traveling to raise awareness of the poor and oppressed in countries like Burma, Uganda and East Timor. She says she is accountable for every cent of her charity's $650,000 budget but questions some of the other efforts.
"I would just like a little bit more knowledge, transparency, accountability as to where a lot of that money goes and what proportion really gets down to the dying child," she said. "I know with our little organization what a huge difference we can make with a little bit of money. I'd like to know where the big budgets go."
Affleck works with UN on Congo refugees
|Actor Ben Affleck and former Congolese refugee Rose Mapendo at the launch of the "Gimme Shelter" campaign in New York|