Programmatically make the iPhone vibrate [duplicate]

Answer 1

To clarify the add(ing) the AudioToolbox framework portion of this answer:

1. click the project from Project Navigator
2. click the target from the left-hand navigator
3. click Build Phases section at the top
4. expand the Link Binary With Libraries section
5. click little + (plus) sign
6. type AudioToolbox.framework
7. click Add

Answer 2

You can use

AudioServicesPlaySystemSound(kSystemSoundID_Vibrate); 

Note that you need to add the AudioToolbox framework and import the following header file:

#import <AudioToolbox/AudioServices.h>