iPhone version 3 software is a must
MobileMe helps you find your lost iPhone.
Sometimes it’s your keys. Other times it’s your glasses. Misplacing things happens all the time. Now, if you misplace your iPhone, Find My iPhone can help you find it.
Locate your iPhone on a map.
Now, if you lose your iPhone, MobileMe can help you find it. MobileMe includes a new feature called Find My iPhone. Just enable Find My iPhone in MobileMe settings on your phone.* Then you can log in to me.com from any computer to access Find My iPhone and display your phone’s approximate location on a map.