add temporary class

jQuery.addTempClass.js

$.fn.addTempClass = function(tempClass, duration){
    if( !tempClass )
        return this;

    return this.each(function(){
        var $elm = $(this),
            timer;

        $elm.addClass(tempClass);

        // clear any timeout, if was any
        clearTimeout( $elm.data('timeout') )

        timer = setTimeout(function(){
            $elm.removeClass(tempClass).removeData('timeout');
        }, duration || 100);

        // set the timer on the element
        $elm.data('timeout', timer);
    });
};

usage:

$(document.body).addTempClass('some_class', 2000)