LOS ANGELES -- It wasn't long ago that Donovan Patton was a struggling young actor who paid the bills by skateboarding around Manhattan's Upper East Side, delivering videos to famous people. Now he's becoming one of those people.

Patton, 24, is taking over as host of one of television's most popular children's shows, Nickelodeon's "Blue's Clues," on Monday, replacing Steve Burns, the show's host since its debut in December 1996.

Burns has become a beloved TV icon to preschoolers, some of whom have been known to shed a tear at the news he's leaving -- making the change akin to Jay Leno replacing Johnny Carson as host of the "Tonight" show for 2- to 5-year-olds.

Patton has been with "Blue's Clues" for more than a year now, filming more than 30 shows. Before that, he had to win over not only the producers at an open casting call, but also tough test audiences of small fry who made sure he could play the "Blue's Clues" game properly.

'They're buddies now'

Indeed, one of the best things about getting the gig, the effusive Patton says, was the opportunity to introduce his 5-year-old sister to Steve.

"They're buddies now," he adds, chuckling. "She thought that was pretty neat because, for a little bit, she thought he only existed inside the television. And now she's gotten to meet him as a real person."

The show, which won a Peabody award last year, seeks not only to entertain but also to prepare children for entrance into kindergarten and the first grade by teaching them to recognize colors, shapes, sounds, words, animals and objects in a world that falls somewhere between fantasy and the typical American living room.

For five years Steve and his animated dog Blue (who is, of course, blue), have embarked on one adventure after another around the house, always by playing "Blue's Clues." It's a game that involves Blue leaving paw prints on three items, each one being a clue to what she wants to do that day.

Steve, who is always a bit slow to recognize a clue, must seek audience help. The result is preschoolers excitedly shouting answers at their television sets.

It's an activity that has been known to enchant some parents and drive others to distraction. The latter seem to fall into the category of those who tire quickly at having to watch Steve, always in his trademark green rugby shirt, fumble to find even the most obvious clues.

The concept was dreamed up by Angela Santomero, a young Nickelodeon research assistant with a master's degree in child development psychology, and animator Traci Paige Johnson.

'I just freaked out'

Though she might be prejudiced, Santomero, who has a 16-month-old daughter, says the show still captivates her, especially when she watches with her daughter.

"One of her first episodes was the one about the farm and she pointed to the cow and said, 'Moo,'" Santomero says excitedly. "And I freaked out. From a parent's point of view, I just freaked out. I said, 'Oh my God, she's learning. And it's from our show."'

Patton, who had rarely seen the show before he landed the job (as a struggling actor he couldn't afford cable television), has quickly come to embrace it.

"It's unique in what it does in trying to make preschoolers talk to the television and have an active part in watching the show," he says.

The only live character in the show is the host, who interacts with such talking animated objects as the end table, the mailbox and the salt and pepper shakers. The actor has to be able to sing, carry on conversations with the animated objects and, most important, display the innocence needed to make children want to help him.