iPhone Cool Projects is the first book to use real applications from the iTunes App Store to demonstrate the tricks of iPhone application development. The iPhone has quickly become the coolest new platform for application development, and developers with all levels of experience and from all development environments are eager to learn how to do it. Not only is there money to be made for developers selling cool iPhone apps, but it’s just a hell of a lot of fun for everyone involved.
A bunch of iDevice creators present guidance and code for a variety of simple applications. There are examples of 2d game apps, audio streaming, network code, game physics, and lots more. I don't know how much experienced programmers would get out of it, but it's a great introduction for those of us who are still Objective-C toddlers.