jQuery effect selector now and in the future WITHOUT an event
<p>Here is an example usage, of what I am trying to do:</p>

<pre><code>  $('img.switchToPng').each(function(){
       currentSRC = $(this).attr('src');
       $(this).attr('src', currentSRC.substr(0, currentSRC.length -3) + 'png');
  });
</code></pre>

<p>Later using ajax a new <code>&lt;img src="path/image.jpg" alt="blah" class="switchToPng" /&gt;</code> appears in the dom, I would like that to NOT require rerunning the selector and each function. With <code>.on</code> selectors in jQuery can live into the future, however I cannot find a way to use it without an event. I could use a <code>'load'</code> event, but that would not be reliable as browser cache may prevent that from firing.</p>

<p>If this is possible, I can see many uses. Does anyone know a good answer to this?</p>
