It depends on what city you are departing from. However Qantas, V Australia, Delta and United all offer direct services from Australia to the US (namely Los Angeles). Qantas also flies to San Francisco and New York and Delta onto Atlanta.
However, Air New Zealand, Air Pacific, Air Tahiti Nui and Hawaiian Airlines all offer services between Australia and the US, however they are not direct.
Using Sydney and Los Angeles as an example, a flight from Sydney Australia to Los Angeles will typically fly northwest out of Sydney, heading over much of the islands of Oceania (such as Fiji and Samoa) in the Pacific Ocean, then over the International Date Line, then the flight will fly over Hawaii before descending into Los Angeles.
Usually you fly west to east across the pacific, as this is the shortest route. You can get non-stop flights in this direction. But you can go the other way too, however you will have to stop somewhere on the way.
The shortest route is towards the northeast (Cairns - Honolulu)
west
Northeast
Southwest
You are more or likely to go west.
Australia
west
You can go either through New Zealand OR fly to Nadi and go form there. If you are already in Western Samoa, Apia you can fly out from there.
If you are going against the wing/gravity you will not go as fast and it will be more of a struggle to fly.
The quickest and most direct route from Australia to South Africa would be to go west.
If you flew across Australia from LaGrange to Sydney, in what direction would you be traveling?
Go Fly a Kit - 1957 was released on: USA: 23 February 1957
As Australia is an island, people have to either fly to Australia or travel by boat. Almost entirely, you travel to Australia by air. Only cruise ships and freight go by sea these days.