Kindle update integrates Facebook, Twitter

Amazon posted info on its site about a new 2.5 software update for Kindle and Kindle DX users that's coming soon. The company says it has begun rolling out the new software update to "a limited group of Kindle users" and plans a broad release in late May. The big news here is that owners of the second-generation Kindle and the Kindle DX will soon be able to share book passages with friends on Twitter and Facebook, and Amazon's also improving its PDF-viewing support with an enhanced pan-and-zoom feature.

Here's the full list of feature updates, according to Amazon:

• Collections: Organize your books and documents into one or more collections.
• PDF pan and zoom: Zoom into PDFs and pan around to easily view small print and detailed tables or graphics.
• Password protection: Password-protect your Kindle when you're not using it.
• More fonts and improved clarity: Enjoy two new larger font sizes and sharper fonts for an even more comfortable reading experience.
• Facebook and Twitter posts: Share book passages with friends on Facebook and Twitter directly from your Kindle.
• Popular highlights: See what the Kindle community thinks are the most interesting passages in the books you're reading.

Alas, owners of the original Kindle will not be eligible to receive the update. But if you own a second-gen Kindle (once called the Kindle 2) or the Kindle DX, you'll receive the update automatically when it's available and your wireless connection is activated.

It's worth noting that this Amazon update comes on the heels of Barnes & Noble's major update for the Nook and it appears that the rivalry between the two $259 e-readers is heating up. As always, feel free to get your two cents in and post your thoughts in the comments section.