In an emergency, i think it's really important to contact my family as well as the emergency services. I carry a phone-card in my wallet (which is a rather understocked urban PSK), so space isn't a problem. I have a cell phone with a very tempermental battery life, so that is yet another reason for carrying a phone card.

We aslo have a 'reverse-charge call' service in S.A., but it can take quite a long time to get connected to an operater, and the music that they play is SO depressing:(