Create an updating animation similar to the facebook iphone app
<p>I have a scrollview with all my data to be showed and I want the user to trigger it being updated. The user should pull the scrollview downwards, then a small view will be shown that was previously hidden and that says: "updating" or "release to update". </p>

<p>Look at the iPhone facebook app and you will see what I am talking about.
They did it pretty awesome, they have a small animation that and an arrow that makes it easy and intuitive. </p>

<p>However when trying to replicate this behaviour I have found that the UI is blocked until the scrollview delegate function was run. This is impractical because I want to update the UI from that scrollview delegate function. 
So when the user holds the scrollview in a dragging motion, there should be a small animation or so that tells him to release it or hold it longer. </p>

<pre><code>- (void) scrollViewDidScroll:(UIScrollView *)scrollView
{    
    CGPoint topOffset = CGPointMake(0, 20);

    if (self.contentOffset.y &lt; 0 )
    {        
        labelUpdate.text = @"Release to update.";

        //do something here to update the UI
    }   
}
</code></pre>
