On one of the Apollo missions (11), a medal commemorating Yuri's first flight was placed on the moon by the NASA astronauts. The medal was commissioned by the British government and contained inscriptions in both English and Russian languages. It was among other items commemorating fallen astronauts/cosmonauts (http://en.wikipedia.org/wiki/Yuri_Gagarin#Tributes)

I'm aware of this because my grandfather hand engraved the medal.