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The actor, who sponsors an environmentally friendly housing project in New Orleans, got his hands dirty in a Patan village near Mumbai, India, as part of the Jimmy Carter Work Project to construct 100 homes for Habitat for Humanity.
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The youngest royal puckers up to a boy at the Mants'ase children's home in Lesotho, South Africa, where the prince launched the charity "Sentebale"
(translation: "Forget Me Not") in memory of his mother, Princess Diana. "[Harry] has inherited his mother's extraordinary empathy," a senior Palace official has said. "He engages with children and young people."
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While visiting New Orleans after Hurricane Katrina devastated the city, the talk show host comforted Mary Lee Quinn, who told Winfrey about her search for her missing relatives. Winfrey, one of the most charitable celebs, gave more than $16 million to help the area last year. Her foundation, Oprah's Angel Network, works globally, aiding children and victims of disasters.
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The former Playboy playmate donned the famed bunny ears when she hosted her "Big Deal" charity fund-raiser at the Playboy Club in Las Vegas to benefit UCLA's Early Childhood Partial Hospitalization Program, which helps children with autism and other disabilities. (McCarthy's son, Evan, was diagnosed with autism three years ago, and since then, McCarthy has been an active spokesperson for Talk About Curing Autism.)
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The singer visited Kenya on behalf of her ongoing cause, Operation Smile, which offers medical assistance to children with facial deformities. "I believe that a smile is contagious," Simpson told PEOPLE. "I believe in this charity and that's why I'm here."
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"A consensus has emerged in our scientific community that global warming is no longer merely a theory but a reality, a crisis with truly global implications for planet Earth and all of us who share it," DiCaprio told the thousands at the New Jersey concert for Live Earth this summer – just one of his many high-profile gigs as an environmental activist. Since 1998, his Leonardo DiCaprio Foundation has awarded millions of dollars in grants worldwide for eco-friendly causes, and most recently co-produced the climate change film The 11th Hour, which DiCaprio himself narrated.
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The singer (pictured bringing gifts to the Mazahua Native Community in Mexico City) does more than just shake her hips: She co-founded the Latin America for Solidarity foundation (ALAS), which in September pledged $40 million to help repair damage caused by an earthquake in Peru and a hurricane in Nicaragua, and Shakira has a second nonprofit to aid child victims of violence (the Colombia-based Pies Descalzos). Of giving, she told PEOPLE: "It is as important as my musical career."
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After the Bourne Identity star visited Africa (here, with a cotton farmer in Zambia) in May, the actor took up the cause to fight poverty and AIDS in the stricken continent. Since then, he's hosted a fund-raiser that raised almost $1.8 million to fight global poverty and is working on a documentary, which addresses the lack of water in Africa. "I feel like I just started down this road – down what's going to be a lifelong trek – but it's most important that we all make it together," he told PEOPLE.
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Instead of the Tour de France, this summer the champ toured the Midwest as part of the Des Moines Register's Annual Great Bike Ride Across Iowa to raise cancer awareness and support increased federal funding to fight the disease. Armstrong, a cancer survivor, was joined by Democratic presidential hopeful Sen. John Edwards (left), whose wife Elizabeth is battling the disease. "Our mission is to make cancer a national priority – just like war would be," the cyclist – who also founded the Lance Armstrong Foundation – told ABC News. "An issue like this that's the number one killer in this country should be a priority."
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The Rescue Me star, whose firefighting cousin and close friend were killed in the line of duty, founded the Leary Firefighters Foundation in 2000 to provide departments with new equipment and training – and has raised more than $8 million. More recently, the foundation donated 15 boats to New Orleans – the first new ones firefighters there had received since Hurricane Katrina. Leary's ultimate aim, he says on the foundation's Web site, is "to give firefighters a better chance of returning home to their families at the end of the day."
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A longtime advocate for PETA (People for the Ethical Treatment of Animals), Anderson turned The Comedy Central Roast of Pamela Anderson into a fundraising event for the organization – and even supported her cause on the red carpet, when she showed up with a carrot bearing a sticker urging people to try vegetarianism.
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The Academy Award winner (and Sexiest Man Alive) has used his star power to shed light on the genocide in the Darfur region of Sudan. He filmed a documentary on the crisis with his father, Nick, a former TV reporter, and has headlined the Save Darfur rally in Washington, D.C. Along with Don Cheadle and California's Gov. Arnold Schwarzenegger, he also supported legislation to limit American business involvement with the Sudan. "It is the first genocide of the 21st century," Clooney has said. "What we cannot do is turn our heads and look away and hope that this will somehow disappear."
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Charity is almost a full-time job for the actor, who founded the Hole in the Wall Gang Camp for seriously ill kids. To date, more than 114,000 children have attended the camps free of charge. Newman also created the Newman's Own Foundation, which donates all profits and royalties from Newman's Own grocery line. To date, the foundation has given more than $200 million to charities around the world.
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The singer, an ambassador for the HIV/AIDS organization Keep a Child Alive, which provides medication, nutrition and childcare throughout six African countries, visited the Masaka Healthcare Center in Uganda, donning a "gomesi," the country's traditional dress. Keys, who over the past few years has made several trips to the continent, told college students at September's Clinton Global Initiative in New York, "We like to say that we're in the business of saving lives and that's the best business to be in for me."
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LL COOL J
Ladies – and kids – love "Cool James," who read the book The Story of Ferdinand to children during a taping of NBC's Today show to kick off Jumpstart's "Read for the Record" campaign. " I was raised in a family of teachers and readers – we had a house full of books," the rapper said. "Reading is the only way to ensure a fulfilling and rich life. It fuels your imagination."
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JENNIFER LOVE HEWITT
The Ghost Whisperer star hosts an annual holiday event at homeless shelter the Los Angeles Mission, dishing out chicken and other items for more than 3,000 men, women and children. "I think this is truly what the season is about," Hewitt has said. "Really, Christmas is about the human connection of man to man, spirit to spirit. You don't get that any better than here at the Los Angeles Mission."