Find My iPhone is now free for anyone with an iPhone 4, iPad, or 4th generation iPod touch (iOS 4.2 required).* Just sign in with your Apple ID on your qualifying device and turn on Find My iPhone to enable your device to be located. Then use the same account to enable Find My iPhone on your other iOS 4.2 devices including iPhone 3G, 3GS, or iPod touch (2nd generation or later). Find My iPhone is also included in the paid MobileMe subscription.
If you lose your iPhone, iPad, or iPod touch while on the go, simply install the Find My iPhone app on another iOS device, launch it, and sign in with your Apple ID (Find My iPhone must already be configured on the missing device).
You’ll see your device’s location on a map and you can choose to have it display a message or play a sound, remotely lock the device, or wipe it to permanently delete all of your data if you think that it won’t be returned. For added security, the app will automatically sign you out after 15 minutes, or you can manually sign out at any time.
• Locate your iPhone, iPad, iPod touch on a map
• Display a message and optionally play a sound for two minutes at full volume (even if your device is set to silent)
• Remotely set a passcode lock on your device, or lock it using your existing passcode
• Remotely wipe your device to permanently erase all of your personal data
Please note that you must first set up and turn on Find My iPhone on each device you want to locate (installing this app is not required).
Supported languages: English, Japanese, French, German, Dutch, Italian, Spanish, Portuguese, Danish, Finnish, Norwegian, Swedish, Korean, Chinese, Russian, Polish, Turkish, Ukrainian, Arabic, Croatian , Czech, Greek, Hebrew, Romanian, Slovak, Thai, Indonesian, Malay, Catalan, Hungarian, Vietnamese
iOS 4.2 and iPhone 4, iPad, or iPod touch (4th generation) for free Find My iPhone
iOS 3.1.3 or later for paid MobileMe accounts
* Find My iPhone enables you to locate your iPad Wi-Fi or iPod touch only when it is on and connected to a registered Wi-Fi network. Find My iPhone is not available in all countries.
Read more: http://www.apple.com/iphone/features/find-my-iphone.html