The 45 million iPhones and iPod Touches sold over the last two years is having a major impact on the worldwide mobile phone ecosystem. Today, nearly half of smartphone web traffic comes from an Apple device. Although the iPhone is still a popular device in the U.S., the number of international users is now growing at a faster rate than here, at least according to the latest Mobile Metrics Report (PDF) from mobile ad firm AdMob.

iPhone OS Geographic Distribution

In the June 2009 Mobile Metrics Report, the focus was on the geographic distribution of the iPhone OS - the operating system that powers Apple's iPhone and iPod Touch. North America is still the largest region with a 58% share. Western Europe is in second at 26%. From there, the percentages drop dramatically, as the chart below illustrates.

As of June 2009, AdMob reports that 54% of iPhone OS users were in the U.S. However, this number has dropped from 61% in January of this year, implying that international growth is now outpacing U.S. user growth. Following the U.S., the other top iPhone/iPod Touch-owning countries include the U.K., Germany, and France, each having over 5% of users.

Not surprisingly, there are far more iPhones in use than iPod Touches. The worldwide ration of iPhone to iPod Touch is nearly 2 to 1, says AdMod. This ratio has remained consistent over the last several months.

iPhone OS Percentage of Smartphone Traffic

Another interesting metric from the recent report is the amount of traffic generated by Apple mobile devices. The iPhone OS literally dominates the charts when compared to the other smartphones worldwide - in fact, it's responsible for nearly half (47%) of smartphone requests. Nokia's Symbian OS is still in a respectable second place with 34% of requests, but then the numbers dip down quite a bit. Blackberry's RIM OS only accounts for 7% of requests, for example, and Android only has 5%. However, AdMob notes that requests from the Android operating system have increased 25% month over month and have, for the first time, pulled ahead of Windows Mobile, which dropped to 4%.

What we can learn from this recent round of data is that the iPhone OS could easily be on its way to becoming a worldwide phenomenon. Although the U.S. still retains the number one spot when it comes to the country having the most iPhones and iPod Touches, the rate of adoption here has slowed. As worldwide growth speeds up, the chart may end up being less lopsided than it is now as other regions gain more users.

Still, you can't count out Apple's competitors just yet. Android's rapid growth is something to keep an eye on, especially as more models of Android phones are introduced. The Palm Pre - only responsible for 2% of smartphone requests - is also too new to the market for anyone to form any definitive conclusions about just yet (although the fact that it registered at all on a chart that features only the major smartphone players is worth noting). All that being said, it's clear that the iPhone OS has a commanding lead when it comes to surfing the mobile web, and that's something that won't change overnight...if it ever changes at all.