Down Under
The term Down Under is a colloquialism referring to things Australian (and to a lesser extent New Zealand). It locates Australia as "The land Down Under" because unlike Africa and South America, that continent lies totally within the southern hemisphere and typically world maps and globes show Antarctica at the 'bottom', with north appearing to be "up" and south appearing to be "down".
Despite the term's widespread international usage, it has been less commonly used by Australians themselves - the exact origin of the term being unknown to most. Because the term apparently did originate elsewhere, this may explain why it lacked a sense of early and immediate legitimacy - to Australians at least. At worst, some 'Aussies' may have initially regarded it as patronising and others as slightly foreign and a little odd when used in standard conversation. Another concern may have been that the words mentally reinforce a perception of geographical distance and isolation from the world.
Nonetheless, the persistency of the media's use of the term (normally in an affectionate or fun way) has led to its wider acceptance and even embrace 'down under'. Its utterance by non-Australians would certainly no longer raise an eyebrow, and when opportunity knocks, Australians are definitely not above making good use of it themselves. A practice exemplified by the Men at Work song "Down Under" which has now become an instantly recognisable, patriotic rallying song - though the writer of the song, Colin Hay, is Scottish. Australia's most famous boxing champion, Kostya Tszyu, was also nicknamed "The Thunder From Down Under".
According to Roger Ebert, "No film set in Australia is allowed to use the word Australia in its title where "Down Under" is an acceptable alternative. For example, we don't get The Rescuers in Australia or Quigley in Australia."