"Find My iPhone" Tracking Can Be Turned Off
Gizmodo has a handy bit of information for all you iPhone owners. That new "Find My iPhone" feature on your phone…yeah, that can be turned off…by the person that stole it.
So, if you wanna steal your friend's iPhone and not have them know where you absconded to, all you have to do it go into Settings, then hit Mail, Contact, Calendars and click on the MobileMe account. Turn off Find My iPhone and all your friend will get is a little yellow warning symbol when they try to track it if the phone's been previously located.