I am not a guy who really love to read books, but recently there’s a few that makes me change my mind. (sorted by purchased date)
Insanely Simple: The Obsession That Drives Apple’s Success by Ken Segall
Tapworthy: Designing Great iPhone Apps by Josh Clark
iOS 5 Programming Pushing the Limits: Developing Extraordinary Mobile Apps for Apple iPhone, iPad, and iPod Touch by Mugunth Kumar