Cause Celebs

Madonna

The singer-songwriter-actress-author-icon is committed to changing the future of children in Malawi. She proves that with frequent trips to Africa for Raising Malawi, a charity she co-founded that funds shelter, nutrition, medical care, and education for more than a million orphans and impoverished children in the country. Right now, the performer is focusing her efforts on the Raising Malawi Academy for Girls. "There's no better way to transform a nation than by empowering its women."

HOW YOU CAN HELP Visit raisingmalawi.org to donate money and find out how to volunteer with the organization.

Kate Walsh

Kate Walsh-who wanted to be a marine biologist in college-swam with sea turtles in the U.S. Virgin Islands to spread the word about endangered marine life. The trip was in support of Oceana, an organization devoted to saving the world's oceans and protecting their threatened species. Spending time with the turtles, she explains, was "very humbling. They're such magical animals, and one of the reasons their existence is in jeopardy is because of commercial fishing and development. I'm hoping to share what I've learned on this trip so people can take much needed action."

HOW YOU CAN HELP Learn more about Oceana and adopt a sea turtle at oceana.org/turtlesoffthehook.

Mary-Louise Parker

"Books were my best friends when I was little," says the Weeds star, who as the new spokeswoman for the literacy group Jumpstart spends time sharing her favorites with youngsters in low-income communities. "I wasn't a social kid, and books were my escape." She loves reading aloud to her son, Will, 5, and daughter, Ash, 3-and applauds the nonprofit's model of building educational skills through one-on-one mentoring. "Books allow you to relate to what you don't understand, which teaches you compassion," says Parker. "It's why I'm so passionate about the organization."

HOW YOU CAN HELP Make a pledge to read to young students at a school, or donate at readfortherecord.org: $50 can provide a preschool with a library of 20 books.

Ben Stiller

The actor joined Bulgari and Save the Children on a recent trip to northeastern Uganda, one of Africa's most impoverished regions, to meet with students and educators and work on building more schools. The trip was part of the Rewrite the Future campaign, which has helped 815,000 children from war-torn areas gain access to education and has trained 25,000 teachers in the past three years. "All these kids are forced to grow up at a very young age," says Stiller. "There's no plumbing, no waste facilities, and they have to walk miles to get to the wells for water. But as much as they are suffering, their attitude is extremely positive."

HOW YOU CAN HELP Give directly at savethechildren.org, or buy a silver pendant necklace that Bulgari designed to benefit the charity at shop.bulgari.com. For each $290 purchase, $60 goes directly to the program and toward its $12.8 million goal.

January Jones

Growing up in Sioux Falls, S.D., 1,000 miles from the nearest ocean, January Jones yearned to be a marine biologist. So it's no surprising that the 31-year-old actress is enthralled with one of the sea's biggest fish. "Sharks are perceived as monsters," Jones told InStyle, but in reality, they are "intelligent and beautiful." To raise awareness about the vital role shares play in marine ecosystems, Jones got involved with Oceana, an organization dedicated to protecting the world's oceans. Naturally, she was a bit frightened before her first big dive in the Bahamas, but she posited, "Hollywood sharks are a lot scarier than the ones here."

Justin Timberlake

As host of a legendary PGA tournament in Las Vegas, Justin Timberlake helped raise $1 million for the Tampa-based Shriners Hospitals for Children. But what really made the singer's day was helping young patients with their strokes at an afternoon lesson. "We're trying to build up the kids' souls, minds and hearts," he said-and up the fun quotient too: Timberlake passed out 22 X-Box 360s to the gleeful girls and boys.

Salma Hayek

Salma Hayek

teamed up with Unicef to eradicate tetanus, a deadly threat that has hit regions of Africa and Southeast Asia particularly hard. Each year the infection takes the lives of 128,000 babies and nearly 30,000 mothers worldwide. "But this disease is 100 percent preventable," Hayek told InStyle. "If we meet our goal, it will be eliminated by 2012." The actress even administered tetanus vaccines herself to at-risk women in Africa. "It was scary," she said. "But it made them so happy to get the shot that it made me happy too."

Brad Pitt

Brad Pitt

is as well-known for his philanthropic endeavors as he is for his leading man looks. In the wake of Hurricane Katrina, Pitt launched Make It Right, a national campaign to help the people of New Orleans rebuild their lives. "We knew we couldn't bring back the families and friends who were lost, bring back the heirlooms and pictures, but maybe, in the process of rebuilding, we could build something smarter to create a better way of life," Pitt has said of his efforts to help the citizens of the Lower Ninth Ward. "Communities need to be rebuilt here and we hope this project points the way to how it can be done using smart sustainable design."

Ali Larter

"We go into various hospitals to read books, play with toys, do different art projects, sometimes just sit with the children and hold their hands," says Ali Larter of her work the The Art of Elysium, which pairs actors and artists with kids battling serious medical illnesses. "It's not changing the world, but it is bringing children a moment of peace."

Tyra Banks

In 1999, Tyra Banks started TZone, which provides grants to community service organizations with programs that empower young women. "There are so many pressures that come with being a girl, and I want to give young women the strength to succeed in our society in which there are so many difficult images to live up to," Banks says.

Jenny McCarthy

"Sometimes I'm on the phone all day, coaching a new mom or figuring out a campaign. It is just what I'm supposed to do," says Jenny McCarthy of her role as the founder of Generation Rescue, an organization she started after her son, Evan, was diagnosed with autism in 2005.

Reese Witherspoon

"Once you have children in your life, you can no longer close your eyes to people...who are in a similar situation," Reese Witherspoon has said. Perhaps that's why the actress and mother is a staunch supporter of another non-profit to be featured on Idol Gives Back, the Children's Defense Fund. The organization works as an advocate for disadvantaged children, and Witherspoon, who is a board member, has personally funded two of CDF's Freedom Schools. Footage of her visit to New Orleans will be screened during Idol Gives Back.

Get a sneak peek of tonight's Idol Gives Back!

Miley Cyrus

Save the Children is a charity close to Miley Cyrus's heart. In 2007, the young Hannah Montana star went to Kentucky with her famous dad, Billy Ray Cyrus, to film a documentary for the organization. Cyrus is also a member of the Red Cross National Celebrity Cabinet.

Bono

U2 frontman Bono has campaigned around the world for The Global Fund. Through the charities ONE and (RED)-an organization supported by products available from companies such as Gap, Apple, and Converse-the Irish rock star has worked to raise awareness of AIDS and Third World debt.

Celine Dion

Canadian songstress Celine Dion has been a patron of the Cystic Fibrosis Foundation for 15 years and several other charities. The chanteuse has traveled to Johannesburg, South Africa and lent her voice to live aid events like Idol Gives Back.

Jennifer Connelly

In 2005 Jennifer Connelly was named Amnesty International USA's Ambassador for Human Rights Education. "In Mozambique I took [my son Kai] around schools and he understood why the children had no books, no paper, no light bulbs. He was so shocked and outraged by it that he wrote a paper for his school, "Connelly has said. "It feels to me a good idea to foster a new generation of Americans who will hopefully be more sensitive to the issues and needs of people around the world."