title: Update browser's URL without reloading the page
body: <p>Is it possible to change the URL shown in the browser's address bar without having the browser go to that page? Such as, for example, after updating a page's content via an AJAX call?</p>
  
  <p>My understanding is that this is not possible, which is why sites such as twitter and facebook update the hash-tag on ajax calls.</p>
  
  <p>That is until today, when I went on <a href="http://8tracks.com/">http://8tracks.com/</a> and started to play with the filter on the right hand side... turning different genres on and off, I noticed that even though it was doing ajax calls to refresh the content on the page, the URL was also being dynamically updated.</p>
  
  <p>Does anyone know how they do this?</p>
  
  <p>(aside, I'm currently using Chrome, but when I went back and looked again with IE9, I noticed that the URL was not being updated.. is this maybe a Chrome only thing?)</p>