I wouldn't be able to own these books without Amazon.com, I'm so happy with it's service.
This time is the turn for both start-up reading and usability:
I've been looking the Interface Design book, and it's by far the best and most complete practical book for usability and interface design book I've ever seen. It's really updated, it has flickr and gmail examples among others. I really like the multiple examples it has, AJAX web interfaces, mobile phones, Windows and Mac, it covers the most common use cases for a modern interface designer. It was a better bought than expected.
PS: Luis, thank you for your recommendations on my last post, it helped to overcrowd my amazon wish list though.