This alternative Kindle, called the DX, is a super-size version of the popular Kindle 2, which arrived earlier this year. It sports a 9.7-inch screen, some 2.5 times as big as the surface area of the Kindle 2′s 6-inch display. It also sports a higher price tag — $489, versus $359 for its smaller sibling, which remains on the market.

Amazon’s Kindle DX

Like previous models, the Kindle DX allows you to shop for, and wirelessly download, any e-book in Amazon’s (AMZN) growing catalog — now about 275,000 titles. It uses the same easy-on-the-eyes screen technology as the smaller model but at a higher resolution. It still lacks color, and renders images only in gray scale. But the new DX adds a new capability: auto-rotation, which allows you to read in landscape mode.

This new, larger model isn’t primarily aimed at readers of standard books. It is targeted at three markets: textbooks, newspapers and other periodicals, and business documents in either Microsoft’s (MSFT) Word format or Adobe’s (ADBE) PDF format.

Unfortunately, I’ve been testing the Kindle DX and I didn’t like it nearly as much as the Kindle 2, which I own and enjoy using daily. While it performs its promised tasks adequately, I found that its size and weight made it awkward and tiring to hold for long periods of reading. It’s still fairly thin and light, but it’s 85% larger and heavier than the standard Kindle.

In addition, Amazon has degraded the user interface. To prevent the device from being even larger, the company had to remove the left-side page-turning buttons, confining all the controls to a vertical strip on the right. The keyboard at the bottom is also more vertically cramped.

If you’re left-handed, you have to spin the device around and rotate the screen to get buttons on the left, where they appear with their labels upside-down.

Similarly, if you choose to read in landscape mode, all the navigation controls, including the joystick for moving the cursor, will be awkwardly placed at either the top or bottom, far from where your hands are holding the device, and the keyboard essentially will be unusable.

In my view, the Kindle DX would have been a better product with on-screen touch controls that could instantly adapt to its size and orientation.

In reading standard books on the DX, I also encountered instances where the text on a page varied in shade from light gray to black.

I had mixed results with business documents. As with previous Kindles, you can either email personal documents to your device, for a fee, or drag them onto the Kindle via a cable, for free. But, unlike the smaller models, the new DX has PDF display capability built in, so it renders PDF files much more accurately than the older Kindles. That is a big improvement. It also allows you to view Excel and PowerPoint files if you save them in PDF format before sending them to your Kindle DX.

The Kindle DX, right, is a large-screen version of the popular Kindle e-reader, left.

I tried a variety of documents, and in many cases the results were great. The text was crisp, and the tables and graphics looked like they should. But I found that on some of these PDF documents, the text was too small to read. Yet, the Kindle lacks the ability to zoom in on PDF documents. You often can make the type larger by rotating to landscape mode, but this splits the PDFs into multiple pages, sometimes breaking them awkwardly.

Also, Amazon has raised its fees for converting and delivering business documents via email to all Kindles. The charge was formerly 10 cents a document. Now, it’s 15 cents per megabyte, which can add up if you load up your Kindle with lots of large documents. Most of my test documents, which were fairly small, cost over $1 each.

Newspapers looked about the same on the DX as they do on the smaller Kindles. Despite the larger screen, they don’t use traditional print or Web layouts, but a special Kindle layout that some users like a lot, but which I find annoying because it makes it harder to quickly scan multiple headlines.

The Kindle DX does have some nice touches. For the extra money, you not only get a larger screen, but also about twice the storage capacity. Also, because the screen is wider, you can adjust the margins on the DX, to obtain a line length that’s comfortable for your eyes and optimal for reading speed.

Amazon claims the same multiday battery life for the DX as for the Kindle 2. In my tests, I was able to go for several days of moderate reading without recharging, and much more if I turned off the wireless capability.

Although I wasn’t able to test college textbooks, I suspect they may be the killer app for this product. Many already are so expensive and heavy they could make the weight and price of the Kindle DX seem trivial in comparison.

But for standard books, I’d stick with the smaller, more comfortable Kindle 2.

Find all of Walt Mossberg’s columns and videos online, free, at the All Things Digital Web site, walt.allthingsd.com. Email him at mossberg@wsj.com.

After being plugged in for somewhere between 5 to 10 minutes I heard a sizzling sound. I looked down on the iPod just in time to see it explode open and start shooting sparks and spewing smoke. I managed to unhook the iPod from my computer’s USB port immediately. I noticed that a small fire had started on the table I had the laptop and the iPod sitting on, and I managed to extinguish those flames quickly before any apparent damage could be done to my laptop. Unlike in other cases, I’ve read about, my iPod continued to spew smoke and spit sparks while throwing out some kind of sooty substance from the inside of the iPod for several minutes after removing the cable from the computer.”

– A Consumerist reader recounts his experiences with Apple’s iPod Flamo

What an ugly week for Apple. Voice and data reception issues plaguing iPhone 3G, MobileMe still not up to company standards and now reports of sparking iPod Nanos. Japan’s Ministry of Economy, Trade and Industry (METI) is investigating a possible battery defect in Apple’s older iPod Nano music players after receiving reports of minor fires caused by overheating devices. “There have been multiple cases of overheating and fire damage, in particular during recharging, so please use caution,” METI said in a statement on its Web site.

METI is working with Apple Japan to diagnose the problem, which is said to affect only Nanos sold in Japan between Sept. 2005 and Sept. 2006, although there have been reports of similar incidents in the states.

Another tough break for Apple (AAPL), which just can’t seem to shake this negative news cycle.

UPDATE: Apple just issued the following statement:

Apple today responded to statements reported by Japan’s METI regarding batteries in the first-generation iPod nanos. Apple has determined that in very rare cases, batteries in first-generation iPod nanos sold between Sept. 2005 and Dec. 2006 can overheat, causing failure and deformation of the iPod nano. Apple has received very few reports of such incidents (less than 0.001 percent of first-generation iPod nano units), which have been traced back to a single battery supplier. There have been no reports of serious injuries or property damage, and no reports of incidents for any other iPod nano model.

Any first-generation iPod nano customers who have experienced their battery overheating should contact AppleCare for a replacement. Any other customers who have concerns about their first-generation iPod nano battery should also contact AppleCare.