For those of you unaccustomed to visas they're stickers that make your passport look pretty. They're also the official authorisation for entrance into and travel within a country or region. Without visas to many countries you'll simply be turned away at the border.
Bestjet.com offers the following Travel Visa service:
It is your responsibility to ensure that all relevant documents are obtained; valid and set minimum validity requirements are met. Different countries require different documents and validity period. You must ensure that their requirements are met before you travel. Bestjet Travel Pty Ltd does not accept liability for incorrect documents or misinformation you receive. Travel delay or cancellation may be incurred if you do not obtain the correct required documents or hold valid documents for your period of travel. You are required to hold a valid passport for international travel with a minimum of 6 months from the date of return travel. Some countries may require a longer validity or a machine-readable passport.
If you have any questions please contact the consulate of the country you intend to travel to for visa advice or visit the Australian Government site:
The Australian Government Department of Foreign Affairs & Trade