Right now I am using the delegate, but I suspect it's bad form.

I programatically create an identical `UIBarButtonItem` in numerous, different view controllers.

My button's target is `myAppDelegate`, and its action is defined therein.

What is a better way of doing this? Or am I just supposed to copy and paste the identical action into no-matter-how-many view controllers that instantiate the identical bar button?

Okay, now suppose the action is identical in all respects but one: It varies only in that it should send a presentViewController message to the view controller that instantiated the button that sent the action. Thus, in the action, I can send a `presentViewController` message to `sender`, which is an instance of the button, but I know no means of reaching the view controller that instantiated that instance of the button.