Amazon's Kindle was recently refreshed for a fourth time. A silver, keyboard-free chassis is the latest theme. We take the company's newest e-book reader through a quick speed test and take a peek under the hood. Some changes are big; some are small.

>Amazon's fourth-gen Kindle hasn't received much fanfare as a result of its tablet announcement. However, the company's new eBook reader features a few changes, along with a significantly lower price tag.

It's part of a dual-pronged approach intended to dominate digital media distribution. While the Kindle Fire tablet is set to take on Apple in the tablet market, the lower-end Kindle represents Amazon's efforts to continue rocking digital book sales.

The newest Kindles come in two flavors: touchscreen and non-touchscreen. But both underwent a drastic facelift. Amazon primarily focused on aesthetics and usability in its evolution. The silver color scheme and keyboard-less design are perhaps the most noticeable changes. However, the company tells us it plans to continue selling the older third-gen black model under the name Kindle Keyboard.

We're still waiting for our Kindle Touch to arrive, but Amazon tells us that there's very little difference between the touchscreen and non-touchscreen models, aside from the touch interface, the presence of speakers, and capacity. All of the Kindles feel the same, as they employ the same stiff ABS plastic case and rubberized plastic coating around back for scratch resistance.

Compared to the previous generation, the lack a physical keyboard makes Amazon's newest Kindles smaller and lighter. However, this changes ergonomics to a small degree.

The "next page" buttons are now embedded along a thinner beveled edge, which makes it a little harder to turn a page, since you go from pressing the surface of the Kindle to trying to squeeze the side.

The device is still connected through a micro-USB connector. Now you have to press down on the Kindle's power button to turn it on, rather than using the Kindle Keyboard's slider mechanism.