With the release of iOS4.2 for all Apple mobile devices, Apple introduced some interesting and finally useful features.
AirPrint - Now you can wirelessly print anything you want from your iPhone to an AirPrint-enabled printer.
AirPlay - Wirelessly stream music, photos, and video to your Apple TV. Or stream music to your AirPlay-enabled speakers and receivers.
And I guess the most impressive is the Find My iPhone - Locate your missing iPhone on a map, display a message, set a passcode lock, or initiate a remote wipe to delete your data.
Click here to find out how to setup your Find My iPhone feature. To find out more go to Apple’s Website