What is the equivalent of 'heads or tails' in other languages?

Answer 1

In Polish it's "orzeł i reszka" - or more formally - "rewers i awers"
"orzeł" is an eagle which is our national symbol and it's present on every coin;
"reszka" is the side of the coin on which the value is printed - the word has Russian origin

PS. You should put this question under the Languages section, you would get more answers ;-)

Answer 2

Well the French is "pile ou face".