Have you ever answered your phone thinking it was someone else? That can quickly happen if you have the same ringtone or vibration pattern for everyone. The best solution is to set a custom vibration pattern for different contacts.
iOS 6 now has several different vibrations and also allows you to create your own vibration that helps you identify why your phone is going off and if it’s important enough for you to leave the meeting, church, class, etc. Here is how you can create your own vibration in iOS 6