Learn how to add your Facebook contacts to your iPhone. By doing this it will pull your friends profile pictures, birthdays and Facebook URLs to your iPhone contacts (names, email addresses, phone numbers) now every time your friends call you, you will see there profile picture automatically.
You can Sync your Facebook Contacts to iPhone 4/4S, iPhone 3GS, iPad and iPod Touch in a few easy steps.
Step 1: Download and install the official Facebook iPhone app from the App store. If you already have installed Facebook app, open the Facebook App on your iPhone and tap on the top left menu button to disclose sidebar.