Device Locator: Track and Locate Your Lost or Stolen iPhone + Google Latitude Integration (iOS) app for $0.99
Keep a running log of your device's location history! If the phone is lost and out of battery or turned off, you will still have its last known location before the phone lost power.
This application can be used to locate a miss placed iPhone or keep tabs on a loved one. To track your loved one or locate your device, the app must be installed on the target iPhone.
Every time your phone changes cell towers, this application will turn on the GPS for 15 seconds and record the best location that your phone can determine. This location is then available online and can be viewed by logging into your account from any computer or phone that has an internet browser.