iPhone code leaks and I don't know why

Answer 1

You are presenting picker but then losing the pointer to it when you leave the method. As it is allocated memory, that is your leak. Try:

UIImagePickerController *picker = [[[UIImagePickerController alloc] init] autorelease];

Answer 2

Shouldn't you be doing an autorelease on the UIImagePickerController?

UIImagePickerController *picker = [[[UIImagePickerController alloc] init] autorelease];

Answer 3

The UIImagePickerController is known to leak. If you are going to use it more than once it's recommended that you reuse a single instance