Exploring iOS 5 feature in iPhone 4

1. Sync iPhone with iTune wirelessly.
 To activate your iTune to use wi-fi sync feature you should have iTune 10.5

Steps to activate Wi-Fi sync in iTune

1. Connect your iPhone to your PC/Mac using wire.
2. Select your iPhone from left side navigation.
3. On right hand side, select Summary Tab; scroll down and check "Sync with this iPhone over Wi-Fi" like shown below                                               
4. Exit and relaunch iTune

 Now lets configure iPhone for Wi-Fi sync. You should have iOS 5 for this.

1. Go to Settings -->General
2. Tap on “iTunes Wi-Fi Sync”
3. Select the computer you set up Wi-Fi sync
4. Tap on the “Sync” button to start the wireless syncing.
5. In case you can not see your sync button activate, try restarting your iPhone.

Note:- Wi-Fi synch will work only when you have connected your iPhone with the power cable to charge your iPhone.

I'll post some images for the steps above later.

I'll add more feature in few days.