Contrary to popular belief, toilets do not drain in opposite directions in the Northern and Southern hemispheres. The direction in which toilets and bathtubs drain is purely determined by their design, and not, as it is often thought, by the Coriolis effect.
An informal reference to a resident of Australia is "Aussie," and an informal reference to the country itself is an even shorter derivative of the word, "Aus." When residents pronounce "Aus" with a hissing "s" sound, it sounds like "Oz," which has resulted in the country's informal nickname of "Oz."
On the Australian flag, the cluster of five stars comprises the constellation of the Southern Cross, which is Australia's geographical location within the Southern Hemisphere. The Commonwealth Star represents the Federation of States as six points and their unity as the seventh point. Aside from the stars, the flag also contains the British Union Jack and a blue field, which symbolizes the flag's historical origins.