// Magic-ness to only run the save callback after no saves have been issued for a while
var executeAfter = function(f, ms)
{
    var timer;
    var wrapper = function()
    {
        var passedArguments = arguments;
        if (timer)
        {
            window.clearTimeout(timer);
            timer = null;
        }
        timer = window.setTimeout(function() {
            f.apply(window, passedArguments);
        }, ms);
    }
    return wrapper;
};

  saveCallback = executeAfter(saveCallback, 500);

// now you can call "saveCallback" with impunity!