Just for interest:  As for South Africa, I have to have some form of
pro forma invoice and go to the bank.  There I have to fill in forms
and apply for foreign exchange.  If this is granted, the bank will
write a cheque for me in U.S. dollars.  I can then post that off.

This annoyance (!) is called "exchange control" and I have to pay the
bank a charge for the application and commission.  They also give a
weaker rate than the standard rate.  There is no other way to get
foreign money unless I can produce a plane ticket.  Then I can get
travellers cheques and cash.  The credit card does work, though.

Regards,
Bernt Damm
Cape Town