. If you have a medical condition, a free app called Close Call can help you in an emergency. It simply adds your emergency contact's phone number, plus any allergies or special medical conditions, to the home screen of your phone.

How else can a cell phone save your life?

often provides during big emergencies. Its page on the Japan earthquake, for example, provides all kinds of information, including a "people finder" where you can find their family and friends.

One of the first things you can do during an emergency is use your cell phone to search the Web for any resource page Google puts up. It usually has them up and running in an hour or two after disaster strikes.

is also very useful in an emergency. The U.S. government's Federal Emergency Management Agency (FEMA), has a full of tips and information. Best of all, the agency will re-tweet important alerts by local agencies. All the major information you need will be broadcast on the FEMA feed.