title: Does NSURLConnection block the main thread?
body: <p>I'm using <code>NSURLConnection</code> in an iPhone application and the interface seems to slow down after sending <code>initWithRequest:</code> to my <code>NSURLConnection</code> instance.  I'm not sure if this is occurring because my processing code is taking a long time to handle the response, or if it's because <code>NSURLConnection</code> is blocking the main thread.</p>
  
  <p>Can anyone confirm that <code>NSURLConnection</code> will create the connection and wait for data on a separate thread, and then call its delegate methods on the main thread?</p>
  
  <p>Thanks!</p>