Get to know how you could enable or disable the call waiting feature on the iPhone 4.
If you are busy and on another call and at the same time when someone else is trying to give you a call, you could suspend the current caller and pickup the second incoming call. This feature is useful when you are expecting a call for a job interview or to get a business deal. You wouldn't want to miss that important call.
Here's how to activate it:
1. Press back to the Home screen.
2. Then select Settings.
3. Next select Phone.
4. Now go to Call Waiting and have it On or Off as desire.
When you disable Call Waiting, while your phone is engaged, it would send the second caller to Voice Mail.