I would have a kindle already if I could somehow transfer my current book collection onto it without having to re-purchase them. It would be perfect for me who has to travel to different nuclear plants around the country and don't want to take up all the room for my books.
Forget the Kindle just get like a used mini laptop that you can trash around then you can read what you want how you want plus play games and stuff when you travel.
I chose the Nook over the kindle because of its reviews by those who have tried both and I am a fan of B&N more than Amazon. Plus the Nook you can add memory to it easier by just buying a microSD card. I have 40 books on mine so far and I have not paid a dime. Got to love the free downloads.