A Motorola Droid smart phone based on Google-backed software hits the US market Friday, taking aim at mobile device powerhouses such as Apple, Nokia, and Research In Motion (RIM).

Droid, which will work on the Verizon telecom network, joins growing ranks of smart phones based on an open-source operating system backed by Internet titan Google.

Taiwan-based HTC brought the first Android phone to market late last year.

Google chief executive Eric Schmidt recently proclaimed that the smart phone market was on the cusp of an "explosion" of Android devices.

Market tracking firm Gartner agrees, predicting that there will be at least 40 models of Android phones within a year, and that they will be the second place mobile platform by the end of 2012.

"In a few years Android will be the second most popular smart phone running neck-and-neck with Apple," Gartner analyst Van Baker told AFP on Thursday.

Apple iPhones have become coveted devices since they were introduced in early 2007.

Early reviews of Motorola Droid have praised the device as perhaps the best Android-based offering to date.

Verizon and Motorola have managed to create a marketplace buzz with mysterious video featuring fighter jets releasing metal pods that slam like meteorites into forest, sea, and prairie.

The pods crack open to give glimpses of Droid devices then end with a cowboy uttering "What in the world is that?" and a message proclaiming Friday the "drop date."

Motorola and Verizon both hope Droid will help them improve lagging positions in the competitive US mobile phone market.

Droid devices are likely to pose more of a threat to Blackberry smart phones made by Canada-based RIM than they are to iPhones, according to analysts.

"It's not an iPhone killer," said Gartner vice president of mobile computing Ken Dulaney said of Droid.

"This is really about changing the mix at Verizon. It will be some attack on RIM."

Blackberry devices dominate the Verizon network, and the Droid offering will give subscribers a tempting option to RIM devices.

Meanwhile, iPhones in the United States are serviced exclusively by telecom colossus AT&T, which has no Android smart phones on its network.

"Droid is not going to draw anyone away from AT&T to Verizon," Dulaney said. "It will keep people at Verizon from going to AT&T and keep some people from going to Blackberry."