Amazon Kindle

• The Amazon Kindle is available in two sizes: the 6-inch Kindle and the 9.7-inch Kindle DX. The 6-inch Kindle can be purchased with just Wi-Fi connectivity or with free 3G and Wi-Fi. The 6-inch Wi-Fi Kindle is $139, while the 6-inch with free 3G and Wi-Fi is $189. The 9.7-inch Kindle DX with free 3G is $379. Prices are as of May 2011. The Kindle gives you access to Amazon.com's large e-book store and supports PDF files, but does not support EPUB files.
  
  

Barnes & Noble Nook

• There are two Barnes & Noble Nooks available for purchase: the regular Nook and the NookColor. In addition to books, the NookColor supports full-color magazines and newspapers. It has an interactive 7-inch touch screen. The NookColor also has an Apps store, giving you access to email apps and game apps, among others. It also supports YouTube and other video. The regular Nook doesn't come with as many bells and whistles, but features the electronic paper display and a 6-inch screen. The regular Nook can be purchased with AT&T 3G and Wi-Fi access ($199) or just Wi-Fi ($149). The NookColor ($249) comes only with Wi-Fi connectivity. Prices reflect May 2011. The NookColor comes with 8 GB of internal memory, while the Nook has 2 GB.
  
  

Kobo Wireless eReader

• The Kobo Wireless eReader is a lightweight e-reader with a 6-inch, e-ink display. It comes with Wi-Fi connectivity and supports both PDF and EPUB files. A big draw is the 100 free, complete pre-loaded e-books. The other popular devices do not come with nearly that many, if any at all. It can store more than 1,000 e-books. The Kobo Wireless eReader is $139 as of May 2011.
  
  

Sony Readers

• Sony offers three different versions of its "Reader": the Pocket Edition, the Touch Edition and the Daily Edition. The Pocket Edition is Sony's thinnest, lightest version. It has a 5-inch full touch screen, holds up to 1,200 books and has a two-week battery life. The Touch Edition has a 6-inch full touch screen, has audio/MP3 capability and holds up to 50,000 books. The Daily Edition is Sony's largest reader. It comes with a 7-inch full touch screen, Wi-Fi and Free 3G connectivity and holds up to 50,000 books. The Daily Edition has a battery life of 22 days.
  
  

Apple iPad

• The Apple iPad is a tablet that can serve as an e-reader. The latest version of the iPad can be purchased with just Wi-Fi connectivity or with both Wi-Fi and 3G. It has a 9.7-inch LED-backlit full touch screen. The iPad comes with its own Books app, but you can also download Nook, Kindle and Kobo apps to it, making it the most versatile e-reader in terms of file types.