$.fn.oneUp = function(options, callback){
    if($.isFunction(options)){
        callback = options;
        options = null;
    }
    settings = jQuery.extend({
        distance: 20,
        speed: "slow",
        callback: callback
    }, options);
    return this.each(function(){
        $(this).show().animate({ 
                top:"-=" + settings.distance + "px", 
                opacity:"toggle" 
            }, settings.speed, function(){
                $(this).css({top: ""}).hide( settings.callback );
            });
        });
};