Amazon.com just started shipping Kindle 2, the new version of its electronic book reader. Now it's making another bold move in the market. The online retailer has started selling e-books on Apple's iPhone and iPod touch. The free Kindle for iPhone application, now available on iTunes, underscores how Amazon is trying to be the dominant player in the electronic book market by making its content available on a range of devices.

Amazon hinted at its mobile phone strategy for e-books just days ahead of the unveiling of Kindle 2, though it kept the details under wraps until now. The company is making its vast collection of electronic books -- totaling some 240,000 -- available to users of the popular iPhone. By selling titles on another device besides the Kindle, Amazon apparently believes there's a market for both the $359 Kindle, which is specially designed for reading electronic books, as well as mobile phones.

Amazon appears to be charging the same prices for e-books on the iPhone and Kindle. New York Times bestsellers and most new releases sell for $9.99, according to Kindle for iPhone app description on iTunes.

Ian Freed, Amazon’s vice president in charge of the Kindle, told the AP that the iPhone app gives Kindle users another way to read content on the fly and introduce them to Kindle as a device.

The Kindle for iPhone application comes equipped with Whispersync, which allows people to switch back and forth between the Kindle and iPhone without losing their reading location. Unlike the Kindle, which displays only shades of gray, the iPhone Kindle app will show e-books in color if they come that way, Freed said. The iPhone app does not include the Kindle 2's text-to-speech feature, which reads e-books aloud and has sparked controversy over copyright issues.

Amazon is no stranger to the iPhone. The company earlier released a shopping application for the popular Apple device. The Kindle joins a growing list of e-book applications for the iPhone, including Shortcovers, from Canadian bookseller Indigo Books & Music, Stanza, eReader and others. But Amazon's digital content will surely help it stand out in the crowd.