Size:

  • Kindle: 8″ x 5.3″ x 0.36″  Kindle DX: 10.4″ x 7.2″ x 0.38″
  • Nook: 7.7″ x 4.9″ x .5″

Storage:

  • Kindle: 1500 books  Kindle DX: 3500 (new not expandable; however old kindle is)
  • Nook: 1500 (expandable with microSD chip)

Wireless:

  • Kindle: 3G connection Kindle DX: 3G connection
  • Nook: Wi-Fi (3G connection)

Wireless Area:

  • Kindle & Kindle DX: World Wide (older model kindle is only US)
  • Nook: Free Wi-Fi in all Barnes & Noble stores

Types of files that can be read:

  • Kindle & Kindle DX: PDF & ebook
  • Nook: EPUB, PDB, PDF, ebook 

Battery life:

  • Kindle & Kindle DX: USB to computer system or power adapter, Charging time: 3 hours from wall outlet.
  • Nook: USB to computer system or power adapter, Charging time: 3.5 hours from wall outlet.
  • They both have about the same battery life

Display:

  • The kindle also has a paper like display, which uses magnetism to bring up ink to the surrface of the “paper” or screen, once it is brought up no energy is needed to continue to view the page. The nook also uses similar technology, however, after reading several comments on the nook there is supposedly more glare with the nook.

I personally have an older version of the kindle (the original), which allows for an SD card to be added (newer versions do not), which could be viewed as a downside. However, there are 2GB on the smaller version of the kindle and each book is up to 2MB, usually only 1.5MB, meaning unless you plan on reading more than 1,000 books, as well as storing them on your kindle there really is no need to have an SD card.

I recommend the kindle.