How To Use Find My iPhone
Find My iPhone can help you locate and secure your iPhone using the free Find My iPhone app on another iPhone, iPad, or iPod touch, or using a Mac or PC web browser signed in to www.icloud.com.
For more details on iCloud; See “how to use iCloud on iPhone.“
Find My iPhone includes:
Play Sound: Play a sound for two minutes.
Lost mode: You can immediately lock your missing iPhone with a passcode and send it a message displaying a contact number. iPhone also tracks and reports its location, so you can see where its been when you check the Find My iPhone app.
Erase iPhone: Protects your privacy by erasing all the information and media on your iPhone and restoring iPhone to its original factory settings.
Important: To use these features, Find My iPhone must have been turned on in iCloud settings on your iPhone before it was lost, and iPhone must be connected to the Internet.
Turn on Find My iPhone: Go to Settings > iCloud, then turn on Find My iPhone.
This article will work on all iPhones using iOS 6; including iPhone 3GS, iPhone 4, iPhone 4S, and iPhone 5.