I am presuming that OP does not have a smart phone or else he would simply use the same WiFi connection to access Skype as he is using to access the internet for his post on FT.

Indeed, if he really is in a pickle, a prepaid cheap phone with a SIM card loaded for calls to the US is the best and cheapest option.

A collect call, if you can make it to an 0170 operator is going to cost the party who accepts the charges an astronomical amount, far more than the a prepaid.

If you are travelling regularly, having a smart phone and a backup is a real necessity.