What's the wealth-making secret of the world's billionaires? For investors on the list, it's sticking to a strategy that plays to their inherent strengths. For many of the others, including five of the top 10, its entrepreneurship.

Oh, to be an owner
You know the list: Microsoft's Bill Gates and Paul Allen, Oracle's Larry Ellison, and Dell's Michael Dell are the four most recognizable names on Forbes' latest list of the nation's 400 richest. Real estate mogul Sheldon Adelson and his $20 billion fortune, comprised mostly of stock in Las Vegas Sands, ranks third and rounds out the list of billionaire entrepreneurs in the top 10.

But there are many more among the remaining 390. Garmin (NASDAQ:GRMN) founder Gary Burrell is 242nd with $1.5 billion. Calamos Asset Management (NASDAQ:CLMS) namesake John Calamos ranks 160th with $2.0 billion. Cablevision's   (NYSE:CVC) chief programmer, Charles Dolan, is 133rd with $2.3 billion. And banking baron Gerald J. Ford ranks 215th with $1.6 billion, a large portion of which he earned selling Golden State Bancorp to Citigroup (NYSE:C) for $6 billion.

Invest with owners
If you're feeling envious, I don't blame you. Wouldn't it be great if we were all billionaires, unencumbered by the need for money? Of course it would be. But that's not how the world works.

Still, I find it reassuring that, as rich as Gates and Allen are, the bulk of their wealth came from staying invested in the company that brought them to the billionaires' ball. Why? Because anyone with a brokerage account could have enjoyed similar percentage gains.

In fact, many did. So great is the story of Microsoft's ability to generate wealth that it has a name -- the uprising of the so-called "Microsoft millionaires." At least hundreds of them must still exist. Consider this chart. A $1,000 investment in Mr. Softy at the dawn of 1990, four years after his debut on the Nasdaq, would be worth roughly $53,000 today.

Searching for the next Microsoft
That's why Motley Fool Hidden Gems co-advisors Tom Gardner and Bill Mann focus on the stocks of up-and-coming firms in which the managers own a significant stake. Some of their best performers still feature meaningful insider ownership.

Consider teen apparel maker Volcom (NASDAQ:VLCM). Tom has twice recommended the stock and earned market-beating results both times. Yet Fools weren't the only ones to profit -- insiders still own more than 40% of the company.

So, don't envy the billionaire owners. Invest alongside them. They're the ones who really have the best chance to create the next Microsoft and make you millions in the process. Want help identifying promising prospects? Click here to join Hidden Gems free for 30 days.

This article was originally published on Oct. 12, 2006. It has been updated.

Fool contributor Tim Beyers owned shares of Oracle at the time of publication. Dell and Garmin are Stock Advisor selections. Dell and Microsoft are active picks for Inside Value. The Motley Fool's disclosure policy always takes ownership.