Who needs men to drive the box office when you’ve got Miley Ray Cyrus (better known to legions of pint-size fans as Hannah Montana), a multimedia starlet who is on track to be a billionaire by the time she hits 18.

The day after Super Bowl XLII, Cyrus—or Hannah Montana, the character she plays on the hit Disney Channel TV show—stole headlines away from one of the most memorable upsets in the history of the National Football League. Her film, Hannah Montana & Miley Cyrus: Best of Both Worlds Concert, became the No. 1 movie at the box office, earning $31.1 million in three days.

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Hannah Montana was shown only at 683 specially-equipped Digital 3-D theatres and moviegoers paid on average $15 per ticket (the national average is closer to $7), but it still set a slew of records: highest box-office total for Super Bowl weekend; highest-grossing opening for a Digital 3-D movie; and highest per-screen average ever—$42,000 per screen trounced the record of $35,000 set by Spider-Man 3 last year. Originally limited to a one-week engagement, the film has now been extended indefinitely. (For more on her movie's effect on U2 3D, read "Hannah Montana Vs. U2.")

Cyrus, daughter of ’90s country crooner Billy Ray Cyrus, who co-stars as her on-screen father, wasn’t done: That same Monday, the movie raked in another $3.3 million. And Tuesday, it earned another $2.8 million, leaving Hollywood insiders scratching their heads. “It was unexpected,” said Jeff Bock, a box-office analyst for Los Angeles-based Exhibitor Relations, “especially for a film targeting young females, which the studios usually don’t target.”

Michael Wood, vice president of TRU, a market-research firm based in Northbrook, Illinois, specializing in tween and youth audiences, says he sees Cyrus on her way to billion-dollar status. “At this rate, she’s certainly positioned to,” Wood says. “I don’t see this ending anytime soon. This is not a fluke.”

Films are just one aspect of the cultural and corporate phenomena that is Hannah Montana. Her talents and earning potential span the spectrum of the entertainment industry in a way that few tween or teen stars—including her fellow minimoguls, Mary-Kate and Ashley Olsen, whose Dualstar Entertainment is a billion-dollar-a-year merchandise business—ever have.

“She’s moved into the space that the Olsen twins used to own,” Wood says. “She has almost more potential. The Olsen twins’ empire was built slowly over many years. But Hannah Montana has risen so quickly she’s exploded into every genre.”

Since her eponymous show debuted in 2006 as the No. 1 cable show for kids age 6-14, she’s had two chart-topping CDs, Hannah Montana and Hannah Montana 2: Meet Miley Cyrus (more than 8 million copies sold worldwide); four bestselling DVDs (more than 2.5 million copies sold); a series of young adult novels (3.7 million copies and counting); video games (1.7 million sold); and a sold-out national tour that has been expanded to 70 dates (and has already generated more than $24 million). (For more figures behind Hannah Montana, see our interactive feature.)

She landed on Billboard’s list of the 20 top-earning artists of 2007 in the No. 11 spot with $64 million from her CD sales and tour receipts, which was good enough to leapfrog over veteran road acts like Faith Hill and Bon Jovi. Perhaps the Olsen twins comparison is a bit unfair—to the Olsens. “This is more like Beatlemania,” says Wood.