Google's Android mobile OS surpassed RIM's BlackBerry OS globally and in the United States for the first time last month, with the Google smartphone and tablet software nearly tripling its worldwide market share to 15.2% over the past 12 months, according to web watcher StatCounter

Android, which still trails Nokia Symbian and Apple iOS worldwide, also topped the BlackBerry OS in North America, 26.4% to 22.2%, with Apple iOS still in the lead at 37.5%. Apple iOS globally has fallen from 33.9% to 24.6% over the past year, though Version 4.3 is now emerging for iPad 2 and other devices, with promised performance benefits.

In the United States, Android blew by BlackBerry OS with a 29.3% share to 23.4%.

The strong numbers for Android come on the heels of reports by ComScore and Nielsen that showed Android atop the US smartphone market. Each company measures the market in its own way, accounting for some differences in rankings.

Android's momentum has been fuelled by a seemingly non-stop rollout of new devices that use the mobile OS, including smartphones like the Motorola Atrix 4G and tablets such as the Motorola Xoom, which runs on the new "Honeycomb" edition of Android.

And in a sure sign of Android's popularity, hackers have begun targeting the Android Market, forcing Google last week to pull down more than 50 malicious apps. 

StatCounter also found in its latest report that the use of pocket-sized mobile devices (so not including iPads and its kind) to access the Internet has more than doubled worldwide from 1.7% a year ago to 4.5%. In the US, the numbers have gone from 2.6% to 6.3%.

StatCounter Global Stats' numbers for February are based on data collected on a sample of more than 15 billion page views from more than 3 million websites.