title: How do you find the "main" picture of a website, given the URL?
body: <p>Let's say you're given <a href="http://nytimes.com" rel="noreferrer">http://nytimes.com</a>
  How would you pull out the "main" image?</p>
  
  <p>The reason I'm asking is because Flipboard is able to grab the main image from a website, just using the URL.</p>
  
  <p>You could parse out all the image tags. But then what?</p>