whenever you need to execute something after an interaction that might happen many times (panning, scrolling, etc) … this simple mechanism makes simple to execute that maybe expensive operations only once when things are "quiet" and never before or in the middle, if an action start as "start panning" would be is fired and it's calling the clear(…

Delayed.js

/*! (C) Andrea Giammarchi */
// https://gist.github.com/WebReflection/7286687
var Delayed = function(delay){
  function Delayed(callback, delay) {
    function delayed() {
      // ensure the right clear method
      clear.call(delayed);
      // re-set the timeout (still waiting after)
      delayed.waiting = setTimeout(
        invoke, delay, delayed, callback, this, arguments
      );
    }
    if (!delay) delay = Delayed.delay;
    // a ways to stop the execution
    delayed.clear = clear;
    // although waiting will be false only once executed
    delayed.waiting = Infinity;
    // **or** if explicitly blocked by a user
    return delayed;
  }
  function clear() {
    if (this.waiting !== Infinity) {
      clearTimeout(this.waiting);
    }
    this.waiting = 0;
  }
  function invoke(delayed, callback, context, args) {
    // mark as consumed already, not waiting anymore
    delayed.waiting = 0;
    // finally invoke the callback
    callback.apply(context, args);
  }
  Delayed.delay = delay;
  return Delayed;
}(500);

few examples on how to in calendar.perfplanet.com

If you are targeting IE < 9 browser you might want to use this snippet to normalize setTimeout extra arguments:

/*@cc_on
(function(f){
 window.setTimeout =f(window.setTimeout);
 window.setInterval =f(window.setInterval);
})(function(f){return function(c,t){var a=[].slice.call(arguments,2);return f(function(){c.apply(this,a)},t)}});
@*/

Apparently jshint get scared by a function referencing this outside an object,
solved by adding /*jshint validthis: true */
after clear() and delayed() method definition,
see https://gist.github.com/kentaromiura/7874867