iPhone SDK shake and vibrate
<p>how can use vibrate when iPhone shaking ? 
here is my code : </p>

<pre><code>#pragma mark -
- (void)accelerometer:(UIAccelerometer *)accelerometer 
        didAccelerate:(UIAcceleration *)acceleration {
   {
        if (acceleration.x &gt; kAccelerationThreshold 
            || acceleration.y &gt; kAccelerationThreshold
            || acceleration.z &gt; kAccelerationThreshold) {


  **//Vibrate it !** 

        }
    }
}
</code></pre>
