title: Centering a span vertically and horizontally within a list item
body: <p>I'm having problems centering a span horizontally and vertically in a list item. It's just sticking in the top left corner. Here's my markup: </p>
  
  <pre><code>&lt;ul id="folders"&gt;
      &lt;li class="add"&gt;&lt;span&gt;&lt;/span&gt;&lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I've set the span to vertical-align to middle, and set the list item text-align to center, but that doesn't help.</p>
  
  <p>I've created a jsfiddle here: <a href="http://jsfiddle.net/Qfars/" rel="nofollow">http://jsfiddle.net/Qfars/</a></p>
  
  <p>Anyone know how I can center this?</p>