Find My iPhone is probably one of the most necessary Apps an iPhone, iPad or iPod Touch owner can download. That's because it will help you track a lost or stolen device. At worst, you can lock or completely wipe the device so that any sensitive information doesn't make it into the hands of someone else.
Note: Apple's press release made it seem that the service would only work on current devices (iPhone 4, iPad and iPod Touch 4G). However, we were able to get it working perfectly on an iPhone 3G running iOS 4.2.
Update: Seems that the reason we were able to update the 3G with MobileMe has been discovered by some users, and just happened by chance on our part.
1) Download Find My iPhone from the App Store on a current-gen iOS device and register.
2) Setup your device by going to Settings > Mail, Contacts, Calendars > Add Account > MobileMe
3) Enter your Apple ID and password.
4) Turn on "Find My …" in the next popup.
5) Now you can launch the App on your current-gen device, and you are ready to go.
6) Now repeat the previous five steps on your older iOS device.
7) Go to Me.com and check that your devices are working.
It's also being reported that you can use someone else's iOS device to setup your account, then just delete your account from the borrowed device. However, it's also noted that you can only create 3 MobileMe accounts per device, even if you delete the account.
Read on for a more detailed walkthrough of the same process with pictures.
1) First, you will have to be running iOS 4.2. You can get it by plugging your device into iTunes, backing up and hitting the update button. iTunes will do the rest for you.
2) Go to your Settings, and choose "Mail, Contacts, Calendars."
3) Tap "Add Account"
4) Choose "MobileMe"
5) Enter your Apple ID and your password.
6) You will see the following screen:
7) Go to Me.com and login with your Apple ID. From there, you can check out the location of your device. Know that you will have to set it up for each of your iOS devices, but the process is the same across the board. You can also download the Find my iPhone app from the App Store, and that will make it possible to track your device from another iOS device.