Implementing jQuery's shake effect with animate

So far I have something like this ..

jQuery.fn.shake = function(intShakes, intDistance, intDuration) {
    this.each(function() {
        $(this).css("position","relative"); 
        for (var x=1; x<=intShakes; x++) {
        $(this).animate({left:(intDistance*-1)}, (((intDuration/intShakes)/4)))
    .animate({left:intDistance}, ((intDuration/intShakes)/2))
    .animate({left:0}, (((intDuration/intShakes)/4)));
    }
  });
return this;
};

I like @phpslightly solution so much, I keep using it. So here it is updated to basic jquery plugin form which will return your element

jQuery.fn.shake = function(interval,distance,times){
   interval = typeof interval == "undefined" ? 100 : interval;
   distance = typeof distance == "undefined" ? 10 : distance;
   times = typeof times == "undefined" ? 3 : times;
   var jTarget = $(this);
   jTarget.css('position','relative');
   for(var iter=0;iter<(times+1);iter++){
      jTarget.animate({ left: ((iter%2==0 ? distance : distance*-1))}, interval);
   }
   return jTarget.animate({ left: 0},interval);
}

You would then use it like a regular plugin:

$("#your-element").shake(100,10,3);

Or use the default values (100, 10, 3):

$("#your-element").shake();

It's actually already implemented this way under the covers, you can see exactly how in jquery.effects.shake.js, if you wanted to copy only that functionality you can.

Another approach to think about: if you're using multiple effects, I'd recommend downloading jQuery UI with only the effects you want. For this effect, without copying the functionality yourself, you would just need jquery.effects.core.js and jquery.effects.shake.js.