gistfile1.js

// more on Event.register: https://prototype.lighthouseapp.com/projects/8886/tickets/477-custom-event-register#ticket-477-4

(function(){
  // mouse:wheel ( DOMMouseScroll )
  function wheel(event){
  	var realDelta;
    // normalize the delta
    if (event.detail){
      realDelta = -event.detail / 3; // W3C
    } else if (event.wheelDelta){
      realDelta = event.wheelDelta / 120;// IE & Opera
    }
 
    if (!realDelta){
      var customEvent = event.element().fire("mouse:wheel", {delta: realDelta});
      if (customEvent.stopped) event.stop();
    }
  }

  Event.register('mouse:wheel', function(){
      document.observe('mousewheel', wheel);
      document.observe('DOMMouseScroll', wheel);
  });

  // focus:in (bubbling focus)
  function focusInHandler(e){
    e.element().fire("focus:in");
  }

  Event.register('focus:in', function(){
    if (document.addEventListener){
	  document.addEventListener("focus", focusInHandler, true);
	} else {
	  document.observe("focusin", focusInHandler);
	}
  });

  // focus:out (bubbling blur)
  function focusOutHandler(e){
    e.element().fire("focus:out");
  }
  
  Event.register('focus:out', function(){
    if (document.addEventListener){
	  document.addEventListener("blur", focusInHandler, true);
	} else {
	  document.observe("focusout", focusInHandler);
	}
  });
})();

gistfile2.js

// NOTE: untested
(function(){
  var events = {};
  
  Event.register = function(eventName, options){
    events[eventName] = Object.extend({
      initialize:  Prototype.emptyFunction,
      setup:       Prototype.K,
      teardown:    Prototype.K,
      handler:     Prototype.K
    }, Object.isFunction(options) ? {
      initialize:  options
    } : options);
  };
  
  Event.observe = Event.observe.wrap(function(observe, element, eventName, handler){
    if (!eventName.includes(':') || !eventName in events) return observe(element, eventName, handler);
    
    var event = events[eventName];
    
    if ('initialize' in event){
      event.initialize();
      delete event.initialize;
    }
    
    if (event.setup){
      event.setup(element = $(element));
    }
    
    return observe(element, eventName, event.handler(handler));
  });
    
  Event.stopObserving = Event.stopObserving.wrap(function(stopObserving, element, eventName, handler){
    if (!eventName.includes(':') || !eventName in events) return stopObserving(element, eventName, handler);
  
    var event = events[eventName];
    if (event.teardown){
      event.teardown(element = $(element));
    }
  
    // !note handler reference is not the same !!! ( event.handler(handler) )
    return stopObserving(element, eventName, hanlder);
  });

});