Amazon rolls out an update for the Kindle 2 and Kindle DX this morning, adding welcome improvements to the company's newest e-readers.

• Built-in PDF reader, eliminating the need to convert those documents to Amazon's proprietary format.
• Manually rotate the screen from portrait to landscape view.
• Battery now lasts 85% longer between charges.
• On the Kindle DX, there's better cropping of PDF files and you can view pages for 20 minutes before the Kindle DX switches into screensaver mode.

Although the update will be rolling out wirelessly over the next two weeks and it will automatically install on Kindle 2 and Kindle DX (sorry, first-gen Kindle users, you're out of luck on this one), there's also a way to manually update your Kindle. It's a simple matter of downloading the file to a Mac or PC, transferring it to your Kindle over USB, and then running the update, which takes about three minutes to install.

Screen Orientation
Changing screen orientation is not automatic — you must push the text button at the bottom row of the keyboard, and then choose the orientation, placing the keyboard on the left, right, top or bottom of the screen. It works well, spreading the text out from edge to edge in either portrait or landscape orientation. Neat.

Native PDF
We loaded a couple of PDF documents, and sure enough, the Kindle to now reads them natively. The problem is, you can't zoom in on the text, so some documents are useless, with the text away too small to see. However, if the text in a document is big enough, this PDF reader works well. Either way, it loads the PDFs quickly and efficiently.

Longer Battery Life
We're looking forward to that longer battery life — Amazon says you can now use the Kindle for a week with wireless connectivity turned on, which would be a great improvement. The company says it's been working hard on this firmware, testing and improving it for six months to extend battery life. Before the update, we noticed our Kindle 2 lasting a mere 2 to 3 days under moderate reading conditions before needing a recharge.

Yay!
It sure is great to get a software update, and these new features will come in handy. Thanks, Amazon — you've made an already-great Kindle 2 just a little bit better.

Via Amazon