Blocks as target/action selectors for UIControlEvents (see my other gist, button_group.m, for an example implementation). Insert this code into any UIButton initializer, whether subclassing or otherwise, to add this event handler.

block_for_action_selector.m

void (^eventHandlerBlock)(void) = ^{
  printf("\nHandling event for button %lu\n", some_local_variable);
};
objc_setAssociatedObject(button, @selector(invoke), eventHandlerBlock, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
[button addTarget:eventHandlerBlock action:@selector(invoke) forControlEvents:UIControlEventAllEvents];

The description is about as useless as the gist is valuable. See button_group.m for sample use.