SIENNA: BUMMED OUT
Sienna Miller may be a fashion trendsetter, but after dressing for the 18th-century period piece Casanova, she won't be lobbying for the return of one outdated accessory. "My enthusiasm for the corset lasted for about a half hour because it really hurts," says the actress, 24, who costars with Heath Ledger. "I was trying to squeeze down sandwiches that would get stuck. And you can't lay down because you've got a bustle [that sticks] out to there. Heath called me 'Big Bum' for four and a half months." At one point, her frustration with her corset got her literally fired up. Says Miller: "I was caught trying to steal it in the middle of the night to torch it."

KUDROW: NORTHERN EXPOSURE
In Happy Endings, Lisa Kudrow plays a masseur's lover, so having her own physical therapist of sorts—her husband, Michel Stem—helped. "Our friend who knows reflexology taught him to do a foot massage," says Kudrow, 42, whose DVD is now out. "He's really good!" Getting kneaded on camera wasn't as relaxing, especially in front of director Don Roos. "Don gets [easily] embarrassed," says Kudrow. "I had to wear a bandeau and it slipped. We were like, 'Oh, no!' He saw my boob, so forget it—we could be married now."

JERRY'S KIDS
While working with 18 children on the family film Yours, Mine & Ours, Jerry O'Connell discovered a barometer for their mini mood swings. "I could tell what kind of day it would be by the candy bowl on set," says the 31-year-old actor. "If it was low I was in trouble, because they'd be all hopped up." But O'Connell, who's engaged to Rebecca Romijn, discovered an easy way to counteract the crashes from the sugar highs: a wad of one-dollar bills he kept in his pocket. Says O'Connell: "Kids are like exotic dancers in that sense—if you give them a little cash, they're happy."

RYAN'S GIRL TROUBLES
As a formerly tormented high school student in the comedy Just Friends, Ryan Reynolds drew upon a personally traumatic experience. "In gym class, where shorts were mandatory, this guy Greg said I should never, ever wear shorts again for the rest of my life because I had the knobbiest knees he'd ever seen," says Reynolds, 29. "He said it in front of this girl I was in love with, and it just crushed me." Years later, Reynolds has found romance with fiancée Alanis Morissette—though not without a challenge. "I even [had to compete for] my current girl," says the actor. "Anything worth having, you're going to come up against resistance. Thankfully I'm good with a blow dart."