title: Setting the thumbnail for safari web previews
body: <p>When I view iCloud.com in my safari top sites, it always always has the same thumbnail.</p>
  
  <p><img src="https://dl.dropbox.com/u/122280/so/preview.jpg" alt="enter image description here"></p>
  
  <p>I'm wondering how I could programmatically do the same for my website.</p>