Gary Marsh | Disney Starmaker
Any 10-year-old girl can tell you why Hannah Montana rocks, or why the Jonas Brothers' music touches her heart. But without the vision of Gary Marsh, president of Entertainment, Disney Channels Worldwide, these pop-culture icons never would have found their audiences. Marsh not only oversees the production of all of the channel's original programming, but also plays a major role in the casting and development of such hit shows as Hannah Montana and JONAS, giving the Disney Channel the top rating spot for kids ages 6 to 11 for the past six years, and for those ages 9 to 14 for the past eight. Marsh, who oversaw the wildly successful High School Musical movies, has an uncanny ability to understand what the next generation wants in their stars and who can provide it. This year's projects included Princess Protection Program, starring tween pop princesses Demi Lovato and Selena Gomez, and the launch of Disney XD, a channel that skews toward the tween-boy demo, extending Marsh's vision to a new audience.

Max Barenbrug | Roll Model
The design of the baby carriage hadn't radically changed in decades. Then Max Barenbrug, founder of Bugaboo Strollers, created a series of brilliant innovations--a removable bassinet and deluxe suspension system, among others. The Bugaboo's most significant advance, though, was the reversible seat and handlebar, which enables parents to change the direction a child faces, increasing parent-kid interaction. In a 2008 study, researchers found that mothers talked with their children twice as much in strollers that faced them as in forward-facing ones.

Arne Duncan | Education Czar
Of all President Obama's cabinet picks, U.S. Secretary of Education Arne Duncan will exert the most influence on our children's future. And though it's early in his semester, his report card so far is good. Duncan, the former head of Chicago's public schools, the nation's third-largest system, is now distributing more than $180 billion in education funds under the economic stimulus plan. He's proving to be a tough, bipartisan administrator and a cheerleader for real change--which can mean bucking teachers' unions. (When the writers of Freakonomics wanted to investigate how Chicago teachers and administrators were doctoring standardized-test sheets, Duncan bravely let them, took their results to heart, and eventually fired a handful of teachers.) According to Freakonomics co-author and New York Times blogger Steven D. Levitt, Duncan is "smart as hell, and his commitment to kids is remarkable. If you wanted to start from scratch and build a public servant, Arne would be the end product."

Robert W. Sears, M. D. | Vaccine Watchdog
No offense to actress/advocate/ mom Jenny McCarthy, but whose opinion should you really seek when it comes to the controversial issue of childhood vaccines? That would be Bob Sears, M. D., board-certified pediatrician and author of The Vaccine Book, part of the Sears Parenting Library. Sears delivers an impartial take on all childhood vaccines, their benefits and possible side effects--and in doing so, he walks the DMZ in the war between public-health

Shigeru Miyamoto | Motion Explorer
This video-game designer was a prominent force behind the development of Nintendo's Wii. Because of his innovations, video games for the first time became tools against, instead of reasons for, obesity. As devices continue to fuse gaming with actual movement, kids will have more incentive to get off the damn couch. And that's the greatest achievement of all. experts who want every child vaccinated and those parents who believe that all vaccines are dangerous. More important, though, he has created an alternative vaccination schedule, which separates shots according to chemical and heavy-metal makeup and delays some vaccines until children are older. Sears feels that we have insufficient knowledge about what the chemical ingredients of vaccines can do to a developing brain. And though he is often vilified as anti-vaccine, by offering an option other than the all-or-nothing approach, he's actually helping more kids get vaccinated.

Mark Zuckerberg and Chris Cox | Facebook Impresarios
With more than 250 million users--a figure that has doubled in less than a year--Facebook's growth rate shows no signs of slowing. For many kids, it has become the preeminent way to chat, gossip, and make plans--for better and worse. Susan Greenfield, D. Phil., a University of Oxford neuroscientist, warns: "Children might become so used to indirect communication that they are simply unable to pick up on the subtleties of face-to-face communication, such as body language and voice inflection." Forbes has called CEO Mark Zuckerberg, 25, the youngest self-made billionaire in history. Chris Cox, himself just 26, is the company's director of products, the man who will chart the future course of a company that aims to become the Google of social networking.

Stephenie Meyer | Queen of Fantasy
She's the Mormon-housewife author of the Twilight series of vampire-romance novels, which in less than four years has become the biggest young-adult publishing sensation since Harry Potter. Meyer's books, New York Times best sellers all, have been published in 43 countries-- the Twilight saga has sold 70 million copies worldwide. At readings, Meyer is greeted like a rock star by screaming Twilighters-- some of whom dress up as her characters. Though the Twilight books sidestep most underage sin, they have so seduced young readers that fans post their own fan fiction, guides, maps, time lines, dictionaries, and other comments on a host of websites for kids, tweens, and even adults.

David Levithan | Wunderkind Pub King
As executive editorial director of Scholastic, David Levithan is spearheading the company's newest project, The 39 Clues, a multi-platform reading project targeted to boys and girls ages 8 to 12. The series will total 10 books (for which Steven Spielberg's DreamWorks SKG has secured all film rights), each written by a different author. Right now, the countdown is on for book six, scheduled to publish in November. But what makes The 39 Clues more than just another kids' book series is that it comes loaded with a host of interactive components--website, collectible cards, games, blogs, and a $10,000 sweepstakes contest. Levithan, 37, got his start at Scholastic as an intern working on the Baby-sitters Club books, and is also an award-winning author of young-adult fiction--his Nick and Norah's Infinite Playlist was made into a movie last year.