Facetime functionality came with the iPhone 4 which has 2 cameras. One on the front and one on the back, both of which can be used by Facetime.
Facetime for iPhone is personal video calling. It actually feels comfortable to use even with other people around due to the personal nature of it. Perhaps it’s the head shot view or the fact that you hold the iPhone 6 inches or so from your face. First up though, you need to setup Facetime
How to Setup Facetime
1. Check that you have turned FaceTime on under Settings
2. Add your Apple ID EMail Address
3. Add your Email address on where you can be reached for video calls.
It’s as simple as that! Now you are ready to make your first Facetime call!
How to Facetime
1. Select the Phone Icon (or Contacts)
2. Choose the person you wish to call and then select the Facetime icon which has a small video camera on it)
3. Wait for your recipient to answer your call!
Note there is no Facetime App for the iPhone 4, although there is one for the iPad 2 and iPod Touch.
You can switch between cameras while you are on your Facetime call by tapping the camera icon.
If you cannot make a Facetime call check the following:
1. Facetime only works on wifi connections. It does not work on 3G connections at present.
2. Make sure your recipient has registered their Apple ID email address through Facetime settings.
3. Make sure you have the correct phone number and email address of course!