Amazon.com has introduced a new generation of Kindle. The all-new Kindle has a new electronic-ink screen in a 21% smaller and 15% lighter design, with 50% better contrast, 20% faster page turns, up to one month of battery life, double the storage, built-in Wi-Fi, with free 3G wireless, and is available for $189.

Amazon also introduced a new addition to its family of portable reading devices, Kindle Wi-Fi. Readers, available for $139. The new Kindle lets users buy their books once and read them everywhere on Kindle, Kindle DX, iPad, iPod touch, iPhone, Mac, PC, BlackBerry, and Android-based devices.

Amazon.com's new Kindle devices

Jeff Bezos, founder & CEO of Amazon.com, said: "Kindle is the best-selling product on Amazon for two years running. We lowered the price to $189 and sales growth tripled. Now, we are excited to introduce a new generation Kindle that is smaller, lighter, and faster, with 50% better contrast.

"If you don’t need the convenience of 3G wireless, we have an incredible new price point–$139 for Kindle Wi-Fi. Kindle Wi-Fi has all the same features, same bookstore, same high-contrast electronic paper display, and it’s even a tiny bit lighter at 8.5 ounces. "

According to Amazon, the new Kindle uses Amazon’s all-new electronic ink display with 50% better contrast for the clearest text and sharpest images; new proprietary screen technology provides faster page turns, new and improved fonts; has double the storage so you can carry up to 3,500 books; Quieter page turn buttons; enables users to start reading books on Kindle in less than 60 seconds; and Kindle Store has over 630,000 books.

Amazon.com's new family of Kindle devices

In addition, the all-new Kindle cover features an integrated, retractable reading light that lets users to read comfortably anytime, anywhere; new WebKit-based Browser; new text-to-speech enabled menus; uses an improved built-in PDF reader with new dictionary lookup, notes and highlights, and support for password protected PDFs.