hi there am with o2 (mods am i allowed to say that) I pay my normal tariff, but also pay an extra £10 a month for 'my europe extra' It means it costs me nothing to recieve a call, and i think 25 p per min to make a call while am abroad. Texts are taken out of your text bundle x4. Some of my colleagues are on a vodaphone tariff where you pay, i think 60p per call connection and the talk time comes out of inclusive minutes. That said I only fly Europe, not w/w. Hope that helps.