Endeavoring to attract new customers to its e-reader Kindle, as well as to retain its current users by expanding the portability of its e-books, Amazon Tuesday launched its highly usable Kindle for PC application.

The release of the new Kindle for PC software, which is a 5.3MB download, will enable the users not only to purchase and read digital books on a PC, but also to synchronize their downloads with other devices, including the Amazon Kindle e-reader.

The availability of the PC app adds to Amazon's enviable list of devices on which e-books can be read - it already sells e-reader software for the Apple iPhone and iPod Touch, over and above the Kindle and Kindle DX. Amazon also intends introducing Kindle software for Apple Macs in the near future.

Though the Kindle for PC is deft at handling the basics of its job, it still lacks one significant feature - that of allowing the users to create annotations; this feature is a part of both the Kindle hardware and the Kindle for iPhone app.

Nonetheless, the new Kindle software for PC allows users to view notes and highlights made on any other Kindle-software device. Moreover, Kindle for PC boasts e-book graphics displayed in color; and, benefiting from Windows 7's touchscreen capabilities, provides users the ability to zoom in and out of text with a pinch of the fingers.