ICE - In Case of Emergency. It's free and easy and could one day save your life.
Put ICE in your cell phone and make it easier for emergency personnel to contact loved ones in case of an emergency to get your medical history (are you allergic to any drugs, do you have a history of heart disease, do you have a Do Not Resuscitate order, etc.).
Make a new entry with the word "ICE" followed by the name of the person you want called in emergency situations (examples: ICE-Dave, ICE-Mom). For more than one contact name use ICE 1-Dave, ICE2-Mom or ICE1, ICE2, etc.). Make sure that person(s) knows your medical history.
Individuals without cell phones should carry an identification card with emergency contacts and medical information in your wallet or purse.