With MooTools Native and Class modules you can write MooTools classes with jQuery

Class.Mutators.jQuery.js

(function(){
 
	Class.Mutators.jQuery = function(name){
		var self = this;
		jQuery.fn[name] = function(arg){
			var args = Array.prototype.slice.call(arguments, 1);
 
			if ($type(arg) == 'string'){
				var instance = jQuery(this).data(name);
				if (instance) instance[arg].apply(instance, args);
			} else {
				jQuery(this).data(name, new self(this.selector, jQuery.extend(self.prototype.options, arg)));
			}
		};
	};
 
})();
/*

// Extend the jQuery object with your class
var MyClass = new Class({
	Implements: [Options, Events],
	options: {
		foo: 'bar'
	},
	jQuery: 'MyClass'
});

// instantiate the class
jQuery('#element').Class(options);

// call methods
jQuery('#element').Class('method','arg','arg', ...);
*/

Person.js

var Person = new Class({
	
	Implements: Options, 

		options: {
			height: 'tall',
			weight: 'fat'
		},

	jQuery: 'Person', // must be after options definition 

	initialize: function(selector, options){
		this.setOptions(options);
		this.jqueryObject = jQuery(selector);
	},
	
	dance: function(whichDance){
		// dance the whichDance
	},
	
	combust: function(){
		// combust
	}

});

usage.js

// instantiate the class
var instance = new Person('#dude',{ height: 'short' });
jQuery('#dude').Person({ height: 'short' });

// call methods
instance.dance('salsa');
jQuery('#dude').Person('dance','salsa');