Amazon just announced the Kindle Touch, which uses an infrared touch display. The device is very small and light and optimized for one-handed reading. The price is only $99 for the Wi-Fi version, and $149 for the 3G version.
EasyReach technology lets you tap toward the top of the screen to access the menu, tap in the middle to bring up the next page, and the left corner for previous page.
Another feature of the Kindle Touch is called X-Ray, which can pull up things such as Wikipedia entries for interesting phrases, historical figures, and more. This side-file is automatically downloaded for you when you download a book, so you don't have to access the web. In general, Kindle X-Ray lets you look at the "bones" of a book, including important events, characters, historical figures.
Not keen on touchscreens? Amazon has also just launched a Kindle without touch for $79, and it's a very portable 5.8 ounces. Stay tuned for more details and hands-on impressions.