Obtaining the correct visa prior to visiting the USA is important. The US Consulates in Australia can provide the information you need. Their website provides a comprehensive description of the various visa options. Additional information on visas and immigration matters is available on the official US Government site. If the Consulate assistance does not meet your requirements consider contacting a US immigration attorney.

Electronic System for Travel Authorization (ESTA) advisory statement

The Electronic System for Travel Authorization (ESTA) is required by the US Department of Homeland Security for citizens of Visa Waiver Programs (including Australia) before entering the USA.

US visa category created exclusively for Australians

The United States has a class of visa, the E-3 visa, which is available only to nationals of Australia, their spouses and children. E-3 principal applicants must be going to the United States soley to work in a speciality occupation, which requires:

  1. A theoretical and practical application of a body of specialised knowledge.
  2. The attainment of a bachelor or higher degree in the specific specialty (or its equivalent) as a minimum for entry into the occupation in the United States.

It is not enough that an E-3 applicant holds a particular degree - the job itself must also require a bachelor level or higher qualification. E-3 workers may be admitted initially for a period of up to two years and extensions of stay may be granted indefinitely in increments of up to two years. There is no limit on the total length of stay for an E-3.