title: Change data-theme in jQuery mobile
body: <p>I'd like to provide my user some persistent feedback after they've pressed a button (like it's indented or something). I tried:</p>
  
  <pre><code>$(this).data('theme','b');
  </code></pre>
  
  <p>But that doesn't work.</p>
  
  <p>Q: Is there a way to show an indented button, or change it's <code>data-theme</code> on the fly?</p>