Sara DeBoer / Retna Ltd. 1 / 19
Sara DeBoer / Retna Ltd. 1 / 19

Anyone who has ogled Megan Fox's thigh-tastic, "ah-ooga!"-prompting promotional pics from "Transformers: Revenge of the Fallen" would deem her figure fault-free. But the brunette knockout has a different take on her on-screen hotness. "[Director Michael Bay] doesn't like really skinny actresses. He's been traumatized by them for some reason in the past," she says (via the London Sun). "So I always try to put on eight to ten pounds before [filming], and I'm always the fattest I've ever been when making a 'Transformers' movie." Fox, who recently admitted to Elle magazine that she slimmed down to a "super, super skinny" 99 pounds for her role in the forthcoming "Jennifer's Body" (she also recently showed off an eye-poppingly cinched waist), fesses up to having no health regimen. "Anyway, my weight fluctuates constantly -- I don't really take good care of myself," she shrugs. "I just sort of exist and survive."

Megan Fox Bares All in Elle

Hayden Panettiere has already done her part to save the whales. Now, the pocket-size "Heroes" cutie, 19, is trying to save her fellow teens from an unplanned visit from the stork. On Wednesday in New York, she joined Bristol Palin at a Candie's-hosted town hall meeting on teen pregnancy prevention. "I want a family. I want kids. I actually want a lot of kids. Not like ten, like four," Hayden, who reportedly split from much-older co-star Milo Ventimiglia in February, tells OK! magazine. "And the only way to be the best mom I can be is by waiting until I'm no longer a child and waiting until I can teach them the best morals and raise them the best I can with a good education and a good platform." Meanwhile, Panettiere's recent lunch date with co-star Adrian Pasdar not only raised eyebrows, but may have also annoyed his Dixie Chicks wife, Natalie Maines. The Chicago Sun-Times claims Maines was ticked that the pair was photographed holding hands, even though it was in a strictly friendly, father-daughter kind of way. "It's appearances that matter in L.A.," a source tells the paper, "and he should know better [than] that."

Even Oprah Winfrey is vulnerable to technological glitches. The media icon tells the New York Daily News that she accidentally deleted her original tribute to Michelle Obama for Time magazine's "100 Most Influential People." "I had written the whole piece on my BlackBerry, and I was feeling really so great about it," she explains. "I wrote it in the memo section, and I went to hit save and I hit another key -- and it disappeared. I lost the whole thing!" Oprah, who had been steadily working on the piece for about a month, "just stared at the BlackBerry for about 30 minutes. I hit every single key to make it come back." It never did, and she had to start from scratch. You can read the results of Oprah's do-over here.

Check out celebrity technophobes

And finally, because there's nothing more enjoyable than stars doing fun stuff, don't miss a bikini-sporting Julia Roberts looking fab and showing off a lower back tattoo featuring the names of kids Hazel, Phinnaeus and Henry; Jennifer Garner multitasking at a Boston playground as she pushes 3-year-old Violet on a swing and cradles 4-month-old Seraphina; Kelly Ripa rippling her quarter-bouncing abs while soaking up the sun; and Nicole Kidman and Keith Urban toting a kicky barrette-sporting Sunday Rose.

Check out Jennifer Garner and other celeb moms

Next: Reese in no rush to become Mrs. Gyllenhaal