You’ve heard of the explosive growth of alternative workplaces and virtual office space. But the potential is so much greater than what we see today.

According to market research firm IDC, the world's mobile worker population will pass the one billion mark this year and grow to nearly 1.2 billion people—that’s more than a third of the world's workforce—by 2013. The most significant gains will be in the emerging economies of Asia/Pacific, where a strong economic recovery and new interest in unified communications will drive healthy growth in all aspects of mobility spending.

"Vast opportunities exist for bringing a variety of mobile technologies to the world's workforce," says Sean Ryan, a research analyst in IDC’s Mobile Enterprise Software group. "Outside the United States and Japan, where mobile worker population penetration has essentially peaked, there are large worker populations that are still growing. Underserved mobile workers across all regions stand to benefit from the reach and flexibility offered by mobile solutions. While some barriers to adoption will still have to be overcome, the potential market for mobility solutions is enormous."

The opportunity may be greatest in the Asia/Pacific, but we haven’t even tapped the full potential of virtual office space in cities like New York or Los Angeles yet. It’s massive. Let’s look at some of the key findings from the IDC forecast:

The United States has the highest percentage of mobile workers in its workforce, with 72.2 percent of the workforce mobile in 2008. The U.S. will remain the most highly concentrated market for mobile workers with 75.5 percent of the workforce, or 119.7 million workers, being mobile in 2013. Can you see the virtual office possibilities here?

Asia/Pacific (excluding Japan) represents the largest total number of mobile workers throughout the forecast, with 546.4 million mobile workers in 2008 growing to 734.5 million or 37.4 percent of the total workforce in 2013. At the end of the forecast, 62 percent of the world's mobile workforce will be based in the APeJ region. Another major driver for alternative workplace strategies in general and virtual offices in particular.

Western Europe's mobile workforce will enjoy a healthy compound annual growth rate (CAGR) of 6 percent over the forecast period to reach 129.5 million mobile workers (50.3 percent of the workforce) in 2013, surpassing the total number of mobile workers in the United States.

Japan's mobile worker population will total 49.3 million in 2013, representing 74.5 percent of its total workforce. Like the U.S., this is essentially the sustainable limit of Japan's mobile worker penetration.

The rest of the world (ROW), which is comprised of Canada and the emerging market countries in Central and Eastern Europe, Middle East and Africa (CEMA), and Latin America, will see its mobile worker population grow to 153.2 million by 2013. As with APeJ, the low penetration of mobile workers in the total workforce (13.5 percent) signals significant growth potential in these markets.

As companies consider how to accommodate mobile workers and others with alternative workplace strategies, virtual offices are emerging as one of the most popular choices because they offer perhaps the greatest flexibility with no need for an investment in bricks-and-mortar space. It will be interesting to see how this plays out in the next decade.