That news came from Andy Rubin, senior director of mobile platforms for Google, at the Google I/O developer conference in San Francisco. He said eight or nine handset makers are manufacturing the nearly two dozen Android-based devices Google knows about, though he declined to reveal the manufacturers or the wireless carriers that will offer them.

Why the sudden flood of Android devices?

"Everybody was wondering if Android was a fluke or if it would be popular. What they are finding out is that Android is not a fluke and it is popular," said Mike Disabato, a senior analyst at the Burton Group. "Now everybody is scrambling to create something that can compete with the iPhone. I would guess that over time we are going to see a lot more Android phones. This is going to be a problem for Apple."

Google's Diversity Advantage

Disabato's guess is based on sound reasoning. Apple only has one handset to choose from, and current plans don't call for a clamshell or slider phone with a QWERTY keyboard. There are even rumors that the new version 3 iPhone won't look any different than the current iPhone 3G. Disabato said that could give Google an edge.

"Google is licensing the software. That's how they are making their money on this deal," Disabato said. "I would guess handset manufacturers are going to make different size and form-factor handsets to hit different ends of the market."

Disabato said there is still a misconception in the marketplace that an Android handset has to look like an iPhone with a big screen -- but it doesn't. Android is an operating system . He pointed to Symbian as an example of an operating system that is on handsets of all kinds, from the low end to the high end. He expects the same scenario with Android.

Impact on the Mobile Web

The emergence of devices such as the iPhone and the Android-based HTC Dream (the T-Mobile G1) that deliver compelling Internet experiences has generated a debate on which Web consumers will use on mobile devices -- mobile Web sites or HTML sites, according to AdMob.

While Gartner estimated global smartphone sales represented 12 percent of total mobile-device sales in 2008, 35 percent of AdMob's worldwide ad requests in April came from smartphones. That means smartphones accounted for nearly three times more usage than their relative market share.

The iPhone operating system had eight percent of the smartphone market but generated 43 percent of mobile Web requests and 65 percent of HTML usage. By contrast, the Android operating system's share of the smartphone market was less than one percent, but generated three percent of mobile Web requests and nine percent of HTML usage.

Of course, it's not all about iPhone and Android. Other operating systems are also seeing plenty of mobile Web usage. Symbian had 52 percent of the smartphone market, but generated only 36 percent of mobile Web usage and seven percent of HTML usage. Overall, usage of mobile Web sites greatly outpaces HTML sites on smartphones running the Symbian and BlackBerry operating systems.