title: API to determine whether running on iPhone or iPad
body: <p>Is there an API for checking at runtime whether you are running on an iPhone or an iPad?</p>
  
  <p>One way I can think of would be to use:</p>
  
  <pre><code>[[UIDevice currentDevice] model];
  </code></pre>
  
  <p>And detect the existence of the string @"iPad" - which seems a bit fragile.</p>
  
  <p>In the 3.2 SDK, I see that <code>UIDevice</code> also has a property which is really what I'm looking for, but doesn't work for pre-3.2 (obviously):</p>
  
  <pre><code>[[UIDevice currentDevice] userInterfaceIdiom]; 
  </code></pre>
  
  <p>Are there other ways than checking for the existence of @"iPad" for a universal app?</p>