Can someone please explain to me why, at the top of page 97, the code is like this:

button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

INSTEAD OF:

button = [[UIButton alloc] buttonWithType:UIButtonTypeRoundedRect];

How does the button object get allocated? Does the 'buttonWithType' method do the allocating itself?

+ (id)buttonWithType:(UIButtonType)buttonType is a class method that handles the allocation and initialization of a UIButton for you (note the + sign in front of the return value). It returns an autoreleased object. Many classes have convenience methods for creating members of the class: e.g. [NSDictionary dictionary], [NSString stringWithFormat:…] etc
In many cases this simplifies (less typing, easier memory management) the creation of a new object. With UIButton it is the only way, outside of Interface Builder, to create a button.
Bob