title: How can I duplicate Pinterest website's modal effect?
body: <p>I would like to create the same effect as on <a href="http://pinterest.com/"><strong>Pinterest</strong></a> when you click on an image: a modal window opens up but the URL of the page also changes. This last part is crucial: the URL in the address bar of the browser has changed, but we still see the original page content in the background (that's why I call it a modal even though it may be much more complicated than that).
  I am ideally looking for a jQuery solution.</p>
  
  <p>[edit]
  I should add that of course the Pinterest behaviour does not break the Back button which is, again, crucial.</p>