As you may have guessed, I like ebooks a lot - they don't take up room on the shelves, I can carry my entire library with me (although I really only take the unread ones), letting me skip to another book as the mood strikes, a backup of my library fits on a single disk and can be stored offsite for recovery in the case of disaster (try that with a thousand or so paper books).
I currently use the Amazon Kindle for reading, but have used other devices in the past, including Palm readers and phones, my HTC phone and an iPod Touch. For those who don't yet have a reader or want to pick up another, and don't mind that it isn't compatible with the Amazon Kindle store, the Sony Reader is another alternative and Books onBoard is giving one away, in Sangria Red! Even though this reader isn't compatible with my Kindle Library, I have more than enough book in PDF, EPUB and eReader formats that this would be a welcome addition here.
I like Books on Board, even though their books are not Kindle compatible, as they can be read on the computer or the iPhone/iPod touch. They have a no-nonsense pricing structure, no club to join and when they have a book with reward dollars offered, you can use your existing reward dollars to buy it. They even have a free book now and then that lets you build you Reward Dollars balance without even giving them any money at all.
Be sure and enter the contest!