Rumors of an Amazon smartphone grow louder

On the eve of Amazon's expected unveiling of new Kindles comes word that we may get a peek at the Internet retail giant's long-rumored smartphone.

The phone, which is reportedly still in development, could make its debut at a press event tomorrow, multiple sources tell The Verge. CNET has contacted Amazon for comment and will update this report when we learn more.

These are not the first rumblings we've heard of Amazon working on a smartphone of its own. The phone will reportedly run a variant of the Kindle Fire Android operating system and challenge the iPhone and Android-based phones.

Citigroup analysts suggested last November that the Seattle-based e-commerce giant was working with Foxconn to develop a smartphone slated for release in the fourth quarter of 2012. Amazon was rumored in July to already be testing such a device with a screen size of between four and five inches.

Amazon has been pretty tight-lipped over what will be discussed tomorrow, but several leaks -- and the fact that it's been nearly a year since the last hardware refresh -- point to a range of new Kindle devices. CNET reported last week that Amazon will debut two 7-inch Kindle Fires at the event, including a high-end model with a zippy processor, a camera, physical volume controls, an HDMI port, and larger storage than a second, more bare-bones version.

It seems likely that Amazon will also increase the resolution on the Kindle Fire's display. It may even subsidize the cost of the device with an ad-supported version, as it has with a lower-cost Kindle e-reader. And it seems all but certain that Amazon will update its Kindle e-ink readers as well, with a "Paperwhite" backlit model rumored. The press conference begins tomorrow at 10:30 a.m. PT. We'll be kicking off our coverage a bit earlier (around 10 a.m. PT). Join us from the Barker Hangar -- yep, the company has rented a hangar -- as we cover the event live.