Got this from email list...
4 Things you might not have known about your Cell Phone
For all the folks with cell phones. (This should be printed and kept in your car, purse, and wallet. Good information to have with you.)
There are a few things that can be done in times of grave emergencies. Your mobile phone can actually be a life saver or an emergency tool for survival. Check out the things that you can do with it:
The Emergency Number worldwide for Mobile is 112. If you find yourself out of the coverage area of your mobile network and there is an Emergency, dial 112 and the mobile will search any existing network to establish the emergency number for you, and interestingly, this number 112 can be dialed even if the keypad is locked. Try it out.
SECOND (Hidden Battery Power)
Imagine your cell battery is very low. To activate, press the keys *3370#. Your cell phone will restart with this reserve and the instrument will show a 50% increase in battery. This reserve will get charged when you charge your cell phone next time.
THIRD (How to disable a STOLEN mobile phone? )
To check your Mobile phone's serial number, key in the following Digits on your phone:
A 15-digit code will appear on the screen. This number is unique to your handset. Write it down and keep it somewhere safe.
If your phone is stolen, you can phone your service provider and give them this code. They will then be able to block your handset so even if the thief changes the SIM card, your phone will be totally useless. You probably won't get your phone back, but at least you know that whoever stole it can't use/sell it either. If everybody does this, there would be no point in people stealing mobile phones.
added by dannysao - i was wondering will this work for iPhone, and tested it worked!!
FOURTH (Free Directory Service for Cells)
Cell phone companies are charging us $1.00 to $1.75 or more for 411 information calls when they don't have to. Most of us do not carry a telephone directory in our vehicle, which makes this situation even more of a problem. When you need to use the 411 information option, simply dial:
(800) FREE411 or (800) 373-3411
without incurring any charge at all. Program this into your cell phone now.
This is sponsored by McDonalds.