title: Which browsers support the `<img srcset...>` attribute?
body: <p>The <a href="http://www.w3.org/html/wg/drafts/srcset/w3c-srcset/" rel="noreferrer"><code>&lt;img srcset...</code> attribute</a> allows different images to be shown to the user dependant on screen resolution.</p>
  
  <p>Which browsers currently (Jan 2013) support this attribute?</p>
  
  <p>Given that this is a useful attribute for users browsing on smartphones, additionally, which mobile browsers offer support?</p>