[bylo]

Mobal is by far the most reliable and probably works in more countries than any other global SIM. While it is relatively expensive, it's probably cheaper to use it for emergencies and until you can find a local, country-specific SIM than to get more global SIMs. Apart from the added cost of global SIMs, look at the threads in this forum that discuss all the problems people have experienced with the likes of United Mobile, Yackie, etc. You will not only have to pay up-front for each SIM but also for airtime for each SIM, then have to keep them active and recharged. With Mobal you pay only if/when you use the SIM and it's charged directly to a credit card. That's much more convenient. Also it will be much easier for your family and friends to reach you because they'll only need to know the single Mobal phone number.