Android is still lagging behind the iPhone in marketshare, with only 9% market penetration in the U.S. (iPhone is around 25%). But according to new numbers from online ad giant AdMob [2], Android actually passed the iPhone in mobile Web use this month.

This is all U.S.-only--internationally, the iPhone is much better established than Android. But here in the States, Android accounted for 46% of online mobile traffic, compared with Apple's 39%. The other players, by the way, don't even enter the picture. RIM's BlackBerry phones are in third place, with 7%, and Palm's struggling WebOS only eked out 3% despite a recent Verizon launch.

AdMob goes even further and separates out the individual devices using both Android and iPhone OS. Motorola's blockbuster Droid snagged 32% of the Android traffic, followed by the older HTC Hero. Embarrassingly, Google's own Nexus One managed only 2% of U.S. Android traffic--that might be the stat that allows us to say definitively that the Nexus One has officially bombed.

As far as iPhone OS, the aging iPhone 3GS had 39% of its OS's traffic, followed by the 2nd-gen iPod Touch at 25% and the iPhone 3G at 20%.

This is great news for Android, and more specifically Google--while it may not have as many users as the iPhone, those users are highly active mobile Internet users. Google, which owns AdMob (these numbers are independent, however), is in a position to capitalize on these active users.

Dan Nosowitz, the author of this post, can be followed [3] on Twitter, corresponded with [4] via email, and stalked in San Francisco (no link for that one--you'll have to do the legwork yourself).