From PEOPLE Magazine Click to enlarge
Traveling to earthquake-ravaged northern Pakistan last Thanksgiving, Angelina Jolie boarded a private plane for the 20-plus-hour journey from Los Angeles without a single Louis Vuitton suitcase in sight. Instead, the 30-year-old other-actress-activist-object of Brad Pitt's affection grabbed a lightweight field bag and, as she usually does, packed the bare minimum:

1. Pakistani dress and head cover (to honor local custom)

2. Pair of sturdy boots (for mountain climbing to distribute blankets and food)

For the three nights she was in the field, Jolie—who was accompanied by Pitt, 42, but left kids Maddox, 4, and Zahara, 16 months, back in town—was her typical low-maintenance self, sleeping on the frozen ground in a tent shared with three other workers and wearing the same clothes day after day. No hairbrush. No makeup. Not even a toothbrush. "She really blends in and is very unassuming," says Guenet Guebre-Christos, representative in Pakistan for the United Nations High Commissioner for Refugees, for which Jolie serves as a goodwill ambassador. "She could have passed for any other Pakistani person."

And when she left the field? Jolie was quick to treat herself to a hot shower, always her go-to indulgence when she returns from relief work. Even then, her beauty needs are decidedly practical: a dusting of face powder, a few strokes of mascara, a dab of Vaseline on her world-famous lips and—voilà!—she's ready to meet the president of Pakistan. "She wants to make a difference," says Guebre-Christos. "She does it with a lot of simplicity."

And frequency. Two months later, it was off to Haiti, where Jolie and Pitt, along with musician Wyclef Jean, visited schoolchildren and met with local leaders to raise awareness and funds for Jean's relief group, Yelé Haiti. Once again, Jolie—in a casual tank top and jeans—dressed for comfort, not luxury. "She looks the most beautiful when she's in the field—natural, no makeup, nothing," says Jean. "Because you see Angelina, the angel. It doesn't get any better than that."

Transitioning between no-frills aid worker and red-carpet-ready Oscar winner is effortless for Jolie, who signed a reported $12 million endorsement deal last fall with St. John with the stipulation that money will go to a charity for children's causes. Says Robert De Niro, who directed her in the upcoming drama The Good Shepherd: "She has a kind of Audrey Hepburnish quality about her but with her own uniqueness."

Like that other beauty icon (and fellow U.N. goodwill ambassador), Jolie can't help but transfix. "There's something mesmerizing about her face," says producer Steve Starkey, who worked with her on the upcoming film Beowulf. "Her smile lights up a room and her eyes are just penetrating."

Still, it's yet another role that reveals the actress at her most breathtaking. Expecting her first child with Pitt any day, the mom-to-be "glows," says Rebecca Matthias, head of maternity-wear retailer A Pea in the Pod, where Jolie stocked up on spring cashmeres and designer denim. "She's probably more beautiful than we've ever seen her."