ICE - In Case of Emergency
A couple good ideas from various sources:
A Cambridge-based paramedic has launched a national campaign with Vodafone to encourage people to store emergency contact details in their mobile phones.
Bob Brotchie, a clinical team leader for the East Anglian Ambulance NHS Trust, hatched the plan last year after struggling to get contact details from shocked
or injured patients.
By entering the acronym ICE for In Case of Emergency into the mobiles phone book, users can log the name and number of someone who should be contacted in an emergency.
Snopes has something about this also.
Plastic-laminate a card with four emergency contacts on one side and any critical drug allergies on the other. Stick it in your wallet next to your driver's license. The license and/or insurance card is all they want in the ER, they won't dig through your wallet if they find those items 1st.