Another great new feature in iOS 5 is the ability to have custom vibration patters. This is a very nice little tweak to help you differentiate alerts while your phone is silent. Now you can assign a unique vibration pattern to anyone in your contacts. You can also change the default pattern for everyone in the Sounds settings.
How To Enable Custom Vibration Pattern in iOS 5
1. Open up the Settings app.
2. Click General.
3. Click Accessibility.
4. Scroll down to the Hearing section and switch Custom Vibrations on.
5. Now open up your Contacts app and select on contact.
6. Click edit.
7. Scroll down to vibration and choose any of the included Standard alerts or create a custom vibration pattern.
8. You will tap on the screen and then press stop when you are done. Pretty cool!
The included Standard Vibrations include: