Who Are The Richest 40 Under 40?

They're mainly 30-somethings and their combined wealth is more than $37 billion.

Some of the newest members of this exclusive club are not only super-rich, they're superstars -- celebrity entrepreneurs who've turned their surnames into brand names.

Fortune magazine launched the list in 1999 when technology stock millionaires seemed to be king of the world. While the dot-comers haven't entirely fallen off the radar, the makeup of America's money men -- and women -- has shifted.

So just who are the 40 richest self-made Americans under the age of 40? Here are some names you might recognize:

No. 40 -- Tiger Woods. The marketing phenomenon is new to the list at the tender age of 25. Just say his name and people think golf a global brand now worth an estimated $150 million.

No. 19 -- Tom Cruise. That trademark smile has helped amass a fortune worth $251 million.

No. 13 -- Michael Jordan. The best-known name on a pair of Nike's is the wealthiest athlete on earth with $398 million. Now it's hard to say which is a bigger brand --Nike, or Jordan.

What's the secret of their success?

It's not education. Only one of the 40, Jeff Skoll of eBay, has an MBA. Another nine went to college, but didn't get a degree and two just have high school diplomas.

If geography has anything to do with it, you better head West. According to the list, the Gold Rush is still in California, home to half of our nation's under-40 gazzillionaires.

If you're looking to marry money instead of making it yourself, you're chances are slim if you're a man. There's only one bachelorette on the list, No. 15, Jeannette Symons, Vice-President of Zhone Engineering, with $374 million.

For women the odds are much better. There are 12 bachelors on the list, including No. 22, Sean P. Diddy Combs, President of Bad Boy Entertainment, with $231 million.

The bulk of this wealth -- three quarters of it, in fact -- still belongs to the computer geeks we've come to know and envy.

No. 1 on this year's list is ... drum roll, please ... Michael Dell, Chairman, CEO and Founder of Dell Computers.

At the age of 36, he's worth $16.3 billion. That's billion with a "B," and this his third year in the top spot. According to Fortune, his non-computer holdings are so vast, Dell stock could lose all of its value, and he'd still be No. 1.

Rosie O'Donnell could've made the list with $113 million but she's too generous. She's given away a lot of her wealth to charity, including her own "4 All Kids" foundation.

Julie Roberts, at 33, is on the brink. Hollywood's "Pretty Woman" gets $20 million a movie and her estimated net worth about $138 million.

And well on her way is Britney Spears. She's just 19 years old and worth $46 million.

Additional Resource:

• See the full list of the 40 richest under 40.