I received this tip from a friend and I'm compelled to pass it on to those not aware of the use of cell phones specially in times of emergencies.

1. Global emergency number is 112.  This number works in out of coverage area  and     can be dialed even if your keypad is locked.

2. If your car has remote keyless entry and you lock your keys in the car, you can call someone at home who has a spare key.  He could press the unlock button on his cell phone on to your cell phone.  You have to stand about a foot from the car door.

3. If your cell battery is low and you don't have your cell phone charger,  press the keys *3370#  Your cell will show 50% increase in battery power.

4. Be sure to check the serial number of your mobile phone by keying in the following:  *06#  When you get your 15 digit serial number, note it down and keep it handy in case your cell phone get stolen. 

5. You get charged  $1.00-$1.75 or more for 411 information on the cell phones.  To get the service free-of-charge, simply dial 1(800) FREE 411.

I didn't figure this out all on my own but I want to pass a good tip to everyone.