Jenai Lane is hot, but she's not bothered. After all, her new line of nail polishes, called P.M.S. (yep, the double entendre is intended), is a hit with the hip. Jennifer Aniston wears it, and talk show host Rosie O'Donnell dubbed it "the mood ring of the '90s." Like the ring, Lane's lacquers change color with body temperature. "It's heat based," she says, "and heat is a reflection of your mood." Proving her point, Lane dips her talons into hot coffee and they turn from Bloated Blue to Pouty Pink. (Tantrum Tangerine, on the other hand, becomes Manhating Melon, and Vexed Violet morphs into Self-Centered Silver.) "People freak out every time I show them," she says. "It's like I'm a magician."

A marketing whiz is more like it. Years before launching her polishes (available at Nordstrom's, Wet Seal and other stores at $7 for the small size and $10 for the large), Lane saw trend potential in her bathtub stopper and chain. "I put it around my neck and thought it was really cool," she recalls. By 1995 she had turned stoppers and other doodads such as O-rings into Respect Inc., now a $1.1 million-a-year novelty item firm.

"I've always been a visionary," says Lane, 30, who was raised in Mesa, Ariz., by psychologist parents. A 1990 graduate of the University of California at Santa Cruz who now lives in a two-bedroom San Francisco pad, she spent three years with a film company until her bathtub stopper brainstorm. Since then, her trend-o-meter has yet to fail. P.M.S. has generated more than $350,000 in sales since hitting the shelves in June. That's enough to turn Lane's Gale Force Green into Glucose Gold.

This week's cover

On Newsstands Now!

VANISHED WITHOUT A TRACE

Heartbreak & Hope

After Jaycee Dugard's rescue, a look at the cases of six young people who went missing in 2009

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