Joining Apple’s iPhone and iPod Touch and the Windows PCs, Research In Motion (RIM)’s popular BlackBerry smartphone line-up now boasts an Amazon Kindle e-reader application, which was launched on Thursday.

Noting that the new BlackBerry-specific Kindle app has chiefly been spurred by the user demand of the RIM smartphone, the Amazon Kindle Vice President Ian Freed said in a Thursday atatement: “Since the launch of our popular Kindle for iPhone app last year, customers have been asking us to bring a similar experience to the BlackBerry, and we are thrilled to make it available today.”

The Kindle application for the BlackBerry can be used by all BlackBerry customers on US carriers including AT&T, T-Mobile, Sprint, and Verizon. The app will enable BlackBerry users to read digital books purchased from online retailer Amazon, as well as coordinate bookmarks with the Kindle e-book reader and other supported devices.

At present, Amazon – which uses proprietary copyright protection technology - boasts an exhaustive availability of as many as 420,000 e-books, which also include 102 out of the 112 New York Times bestsellers.

It is via the Whispersync wireless technology that users can download the e-books, purchased from Amazon, to the Kindle or to any other device that supports the Kindle application. Furthermore, e-books purchased on one device is also made accessible to other devices by Amazon.