Amazon Kindle Software Update Includes Public Notes, Recommending's latest Kindle software update offers public notes, "real" page numbers and new layout for periodicals. The e-reader market seems ripe for continued growth. is tweaking its Kindle e-reader software with the addition of new features such as public notes and e-book page numbers that match those in the print editions.

Amazon has grouped these free updates together as Kindle Software Update Version 3.1, downloadable via a page on its Website. In addition to public notes, a feature that opens Kindle users' book notes and highlights to an audience, and "real" page numbers, presumably good for classes and book clubs looking to reference and sync their reading, the new software includes a new layout for newspapers and magazines.

Kindle users who are dead-set on sharing (or over-sharing) their reading experience with everyone in the vicinity can also use the software update to immediately rate an e-book upon finishing, share messages about that book with their social network, view more books by the same author and receive "personalized" recommendations for their next book to read.

Although Amazon remains reluctant to share any hard data related to sales of Kindle e-readers, the online retailer perpetually claims the device is among its bestselling. In late January, it reported sales of 115 Kindle books for every 100 paperbacks moved through its Web storefront, a number that apparently includes sales of books without an equivalent electronic edition, and excludes free Kindle e-books. Kindle e-book sales had already surpassed that of hardcovers, according to the company.

Research firm Gartner estimates that e-reader sales will increase 68.3 percent in 2011, to more than 11 million units.

"The connected e-reader market has grown dramatically during the past two years, driven by sales of Amazon e-readers, primarily in North America," Hugues De La Vergne, principal research analyst at Gartner, wrote in a Dec. 8 statement posted on Gartner's corporate Website. However, "growth in North American and other markets will remain constrained by the success of media tablets, such as the Apple iPad."

Gartner viewed full-color tablets such as the iPad as the greatest threat to the e-reader market, one that some e-reader manufacturers are trying to anticipate with the introduction of color screens. Barnes & Noble's Nook Color, arguably the most prominent example, includes a full-color 7-inch display, WiFi capability, Web surfing and the ability to share selected passages from e-books via Facebook and Twitter.

Amazon has kept the Kindle a grayscale device, essentially betting its e-reader empire on the theory that most customers will want a device exclusively for reading in addition to their other gizmos. In addition, Amazon offers Kindle software for a variety of devices, including PCs and the iPad, along with an in-development Kindle for Web application, which will allow users to purchase e-books via a Website and read them within the browser.