jquery.centered.js

/**
 * Centers an element
 *
 * @param element Element to center
 */
;(function($){
    $.fn.centered = function(){
        return this.each(function(){
            var element = $(this),
                parent  = element.parent();

            element.css({
                position: 'absolute',
                left:     (parent.width()  - element.width())  / 2,
                top:      (parent.height() - element.height()) / 2
            });

            return element;
        });
    }
})(jQuery);