Record the serial number of every device you have—especially your cell phone. Your phone constantly transmits its serial number to the provider's network, enabling you to trace the phone in cases of theft.
Contact your cell phone provider and report the theft of your phone. Provide your serial number, which should allow your provider to trace the phone. At the very least, ask to have the phone deactivated, which will prevent it from making any calls at your expense.
Contact the police or other law enforcement and provide the serial number. These agencies also have access to tools that can help track down your phone as well.
Provide a description of your phone and its serial number to pawn shops in the area where the theft occurred. If the thief tries to sell your phone, the pawnbroker will have recorded the serial number and have a record of who stole it as well.