Android use rockets by the iPhone in the U.S.

Android phones accounted for more traffic in the U.S. than the iPhone in March, according to a new report from the mobile ad network AdMob. Is this the wave of the future, or a one-time event?

The AdMob report on Android use shows that the Android OS had 46 percent of all smart phone traffic in the U.S. in March, compared to 39 percent for the iPhone. That's a dramatic turnaround since December, when the iPhone had 47 percent, and Android 36 percent.

The number of Android apps are also skyrocketing, with TechCrunch reporting that there were more than 38,000 Android apps as of a few weeks ago, compared to 8,000 the previous month. The numbers still are far below iPhone apps, but with growth that explosive, the Android will continue to catch up to the iPhone.

Worldwide, AdMob reports, the iPhone still leads by a 46 percent to 25 percent margin. But consider that in December, the iPhone was at 50% and Android phones at 19 percent. That means that Android phones closed the gap considerably, from 31 points, down to 21 points, in only a few months.

What does the future hold? Android growth continues to accelerate, and given that many different carriers offer Android phones, versus one for the iPhone, this is clearly a problem for Apple.

In the future, if you don't count the iPad as mobile traffic, Android phones will most likely continue to beat iPhones in the U.S. and eventually overtake it overseas. However, with iPad traffic included, I'd bet on the iPad-iPhone combination.

As for Windows phones, they continue to lag. Microsoft is hoping that Windows Phone 7 will turn that around, but by its release date, it may be too little, too late.