1.  The worldwide cellular emergency number is 112. If you are out of a coverage area dial 112.  Your cell will search any existing network to establish the emergency number for you. 

2.  You can unlock your car by calling the person who has your other keyless remote and asking them to press the unlock button next to their phone while you hold your phone right next to your vehicle.  Dial 112 if you are out of a coverage area.

3.  Press *3370# to activate a 50% hidden battery reserve that will replenish when you charge your phone.   This can help you if you're locked out of your vehicle and your phonhe is dead. 

4.  Press *#06# to discover your 15-digit serial and write it down in case your phone is stolen.  Give this number to your provider so that your phone can be deactivated in the event of a theft -- the phone will not work even if the thief replaces the SIM. 

5.  Instead of paying for 411 calls, use 800.FREE411 or 800.373.3411 instead -- you won't incur any fee at all.