More and more, it seems, the line between childhood and adulthood is blurring.

And when it comes to the domains that once belonged solely to kids, especially extreme sports like skating and snowboarding, "adolescent adults" have a passion to play -- and powerful pockets to pay for fancy equipment, special gear and other merchandise.

"Snowboards aren't cheap. They're really expensive and only grownups can basically afford them," said Hose Cedeno, a spokesperson for the sports equipment maker Blades Board and Skate.

A recent study by the MacArthur Institute says that age 34 is the new 18, and hitting 50 is like turning 30.

And these adults who are young at heart play harder than their parents did when they were that age. It's a group that's 76.1 million strong with an annual disposable income of $930 billion.

As a result, the retail industry is salivating. Scooters and skateboards, for example, used to be strictly kids' stuff. Now manufacturers are making them for adults.

And men who are holding onto their youth are one of the hottest markets, according to some.

"Gadgets, gears and girls: the three G's," Maxim magazine's Steve Russell said. "I think a real important thing to consider in this trend is that men are living much longer than they used to. If you're going to live until 80 years old, why stop having fun when you're 30?"

Indeed, perhaps the world's most famous skateboarder is 34-year-old Tony Hawk, who still skates regularly and is the only person ever to perform a 900-degree turn. 

But women, who are surfing and snowboard in record numbers, are also in on the act.

Some say the need for fun and such on-the-edge excitement is fueled by a fear of commitment, but others say it's just a temporary escape for those who are already over-committed with work, friends and love lives.

"When you look at the reality, these people have made commitments to their jobs, they've made commitments to their family, they really seem to have no problem with commitment," psychologist Georgia Witkin said. "They plan to get married, just not yet, and in the meantime it's all about them."

So enjoy the snowboards, hiphuggers, scooters and skates, said Witkin.

Meanwhile, as the Peter Pan set goes through a second adolescence, retailers are making big bucks off of what they call the new-generation market.