[Plugin: User Specific Content] logged in and logged out shortcode

There is none but here is a quick one for you:

add_shortcode('USER','show_user_content');
add_shortcode('GUEST','show_guest_content');

function show_user_content($atts,$content = null){
	if (!is_user_logged_in()){
		return "this is for looged in users only";
	}
	return $content;
}

function show_guest_content($atts,$content){
	if (!is_user_logged_in()){
		return $content;
	}
}