In Polish it's most typically called just "Facebook", but jokingly also "twarzoksiążka" (where "twarz" = "face". "książka" = "book"). Occasionally also "pejsbook", where "pejs" is a "payot" in Polish, and the name is an ironic pun on Zuckerberg's Jewish background.
In Serbian we call it Фејсбук (Fejsbuk) or shortened Фејс (Fejs). We don't usually translate a foreign site, but we do like to transcribe it (respell it).
Jokingly (and rarely) it would be 'лицокњига' (licoknjiga) лице=face, књига=book.