from the fine folks at Unicel:

Using your phone in an emergency has recently taken on a whole new meaning. A new concept taking hold across the nation is ICE: In Case of Emergency.

Police and other emergency workers will often look into a person's wireless phonebook to try and find out who they should contact in an emergency situation. An Ambulance driver in England came up with the idea of ICE after struggling to get contact details from shocked or injured individuals.

You can help in such a situation simply by adding the word "ICE" to your phonebook and including the name and number of the person you want contacted on your behalf.