04/25/2011 at 01:00 AM EDT
Advocate for: St. Bernard Project
"I love using my voice and my hands to build homes for people who are still in need," says Lutz of his work for the organization dedicated to helping Katrina survivors.
To learn more, go to: stbernard project.org
Advocate for: Warren Easton Charter High School
"The students make me feel confident that our future is in very capable hands," says Bullock of the New Orleans high school she helped rebuild post-Hurricane Katrina.
To learn more, go to: warreneastoncharterhigh.org
"This issue really resonates with me as a father," says Damon, whose organization helps people in developing countries gain access to safe water.
To learn more, go to: water.org
Advocate for: Save the Children
"I don't believe we have to accept childhood poverty as an unsolvable problem," she says.
To learn more, go to: savethechildren.org
Cofounder: Not on Our Watch
"For the few of us who have gotten very lucky in life, there are scores who haven't. It seemed to me that the people of Darfur and south Sudan are some of the unluckiest. Anything I can do to help is the least I can do."
To learn more, go to: notonourwatchproject.org
Founder: Checotah Animal, Town, and School Foundation
"I created a foundation and through that was able to build an animal shelter in my hometown. To see love is to see the face of a pet."
To learn more, go to: thecatsfoundation.com
Advocate for: Food Bank for New York City
"The basic need of food for our nation's hungry children must be a priority," says the Food Network chef.
To learn more, go to: foodbanknyc.org
Founder: Happy Hearts Fund
"We bring education to children after natural disasters," she says. "Seeing their suffering pushes you to make a difference."
To learn more, go to: happyheartsfund.org
Advocate for: Project Cuddle
"This organization saves babies from abandonment or worse," says Stamos. "My involvement is the most important thing I've done in my life."
To learn more, go to: projectcuddle.org