Five years ago, as a fresh-out-of-college reporter, Maria Menounos spent several weeks in South Africa covering the AIDS epidemic for the teen news network Channel One. On camera, the former Miss Massachusetts Teen USA displayed her signature poise as she and her crew traveled to the country's most impoverished areas.

But behind closed doors, she could barely hold it together. "I was hit with a tornado of emotions," says Menounos, 28, the daughter of Greek-immigrant parents who always taught her to put herself in other people's shoes. Menounos was especially jarred by the suffering of children: the 13-year-old boy she met who was caring for his HIV-infected mother; the infant orphan she held in her arms one day, and mourned at a funeral the next. "Right away," she says, "I felt the call to do something."

Once stateside, Menounos gathered clothes, toys, and school supplies to send to the orphanages and villages she'd visited. Still, she wanted to do something bigger. Together with a friend, director Keven Undergaro, Menounos founded Take Action Hollywood! (TAH!). As a correspondent for Today and Access Hollywood (who has also recently added actress and director — of the independent film Longtime Listener — to her résumé), Menounos has been able to rally a host of Hollywood do-gooders to the wide range of causes that matter to her. She's tackled issues from girls' self-esteem to pet overpopulation (Menounos herself has adopted five rescue and shelter dogs), and she's currently raising money to produce a film on the AIDS crisis in South Africa. "Growing up the way I did, not speaking English, helping my parents sweep nightclubs to make ends meet," says Menounos, "I feel such an obligation to stand up for as many causes as I can. I don't want to leave anything out."