Class.Mutators.jQuery.js

Class.Mutators.jQuery = function(name){
	var self = this;
	jQuery.fn[name] = function(arg){
		if ($type(arg) == 'string'){
			var instance = this.data(name);
			if($type(instance[arg]) == 'function'){
				var returns = instance[arg].apply(instance, Array.slice(arguments, 1));
				return (returns == instance) ? this : returns;
			}
			if(arguments[1] != null){
				instance[arg] = arguments[1];
				return this;
			}
			return instance[arg];
		} else {
			if(this.data(name)) return this.data(name);
			this.data(name, new self(this.selector, arg));
			return this;
		}
	};
};

Person.js

var Person = new Class({

  Implements: Options, 

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

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

  awesome: true,

  initialize: function(selector, options){
    this.setOptions(options);
    this.jqueryObject = jQuery(selector);
  },

  dance: function(whichDance){
    alert(whichDance);
    return this;

  }

});

usage.js

// regular javascript api
var bob = new Person('#dude',{ height: 'short' });
bob.dance('salsa'); // dances the salsa and returns bob
bob.awesome; // returns true
bob.awesome = false; // set the property to something else

// jQuery api
$('#bob').person({ height: 'short' }); // instantiate with options
$('#bob').person(); // returns the class instance since it's already been instantiated
                    // or in other words, returns and object like `bob` from above
$('#bob').person('dance', 'salsa'); // dance the salsa and returns the jQuery object
                           // because the class returns `this`, (magic from the mutator)
$('#dude').person('awesome'); // returns true, not the jQuery object because the
                              // method doesn't return the instance, it returns a value
$('#dude').person('awesome', false); // reassign the property