Late last year, Wynn Resorts CEO Steve Wynn was spending two hours each day on Chinese lessons. At age 65, Wynn is worth $3.4 billion -- yet he's still learning new tricks.

Why? Because the Wynn Macau -- Mr. Wynn's latest megacasino -- was getting set to open just off the coast of China. That's right on the doorstep of some 3 billion potential customers.

Big bets for big paydays
How has the Wynn Macau fared? It's already pulling in more revenue than its sister resort in Las Vegas.

But Steve Wynn isn't the only billionaire going gaga over foreign markets. Wynn rival and Las Vegas Sands CEO Sheldon Adelson, himself worth $26.5 billion, is making a similar investment in Macau's potential. Then there's Diageo (NYSE:DEO), which recently acquired more than a 40% share of China's Sichuan Chengdu Quanxing Group to build out a domestic liquor brand in that country. And Intel (NASDAQ:INTC) is putting up a $2.5 billion manufacturing plant in China -- the country that President and CEO Paul Otellini calls Intel's "fastest-growing major market."

Entrepreneurs and investors alike
Meanwhile, there are the master investors who have been buying up Chinese stocks at a rapid clip. Fidelity Magellan's (FMAGX) Harry Lange has $250 million in Suntech Power (NYSE:STP), Davis Selected Advisers owns China Life Insurance (NYSE:LFC), and New York's Horizon Asset Management continues to increase its stake in China Southern Airlines (NYSE:ZNH).

Even Warren Buffett stoked the international frenzy early last year, with purchases of PetroChina and Israel's Iscar Metalworking.

The question we have to ask
So -- and you had to know I was coming around to this -- what have you been adding to your portfolio lately?

Me? I know I'm underexposed to international stocks, and I've resolved to make 2007 the year I do something about that. One place I'm set to start is at our new Global Gains international-investing service. You can join me free for 30 days by clicking right here.

This article was originally published on Jan. 19, 2007. It has been updated.

Tim Hanson owns shares of Wynn Resorts. Diageo is a Motley Fool Income Investor recommendation. Intel is an Inside Value choice. Suntech is a Rule Breakers pick. No Fool is too cool for disclosure.