I was invited to Poland in 1989. This was before the fall of the Berlin Wall, while Poland was still a member of the Warsaw Pact. It had a new government, though, because Solidarity had won all the seats it had been allowed to contest in the recent election, and the Farmers' Party, previously allied with the Communists, had switched sides. The new government wanted to learn how to implement privatization, and the Adam Smith Institute knew about that. Just to be on the safe side, though, we took a Channel 4 TV 'Dispatches' team with us to film it for later broadcast. Even so, we were met at the airport by guards with sub-machine guns.
The conference went well, and we all celebrated with our hosts at the farewell dinner. As we prepared to pay, the restaurant told us they only accepted Polish zlotys. This caused consternation because none of us had any. They didn't take credit cards, either. One of our resourceful members solved the problem by going to the door onto the street and calling out "dollars!" Within seconds a small crowd had gathered, eagerly offering us zlotys for our dollars at the black market rate, much higher than the official exchange rate. The pile of Polish currency we paid with was about the size of a cushion.