Hi all. I'm heading to Malawi and Zambia in a month and will need to talk to people in the US regularly. But of course I don't want to pay the exhorbitant prices that US cell companies charge for international roaming. So if I have an unlocked GSM phone and buy local sim cards in these countries, is it possible to call the US with them? How much would it cost ? Am I better off taking an international sim with a US phone number (onesim, for instance) with me and having my people call me on that (at 20 cents per minute cost to me)? Thanks in advance for the help!