The GeoSIM is a global SIM card that you can use almost anywhere in the world. It works in over 100 countries and while call rates vary the prices don’t seem too exorbitant and in some countries you can even receive calls and text messages for free.
The GeoSIM card works slightly differently to your ordinary SIM, when you ring someone, you wait a few seconds and then your phone will ring and the call will start. You will need an unlocked phone to use the GeoSIM or you can pick up one of their SIM PIG cards and it will apparently bypass the network lock on your phone without affecting the warranty.
The GeoSIM works in 99% of GSM handsets, any credit you purchase lasts at least 12 months and you can even use it for data if you were desperate but the prices are pretty far out (Australia seems to be the worst?!) There’s a lot of detail on the GeoSIM page so you might want to do some research.
Simply swap your existing SIM card for GeoSIM and switch on your phone. Enter your PIN. GeoSIM will then lock on to the strongest local GSM mobile phone network.