When the user stops scrolling, do something

scroll-stop.js

(function($) {
	"use strict";
	$(document).ready (function(){
		$(window).scroll(function(){
			clearTimeout($.data(this, 'scrollTimer'));
     			$.data(this, 'scrollTimer', setTimeout(function() {// when the user stops scrolling
     				// do something
     			}, 500));
		});
	});// end document ready
});