Getting More Australia Out of Your Travel Dollars : Air passes: The best way to see many countries--or just huge ones--is with discounted tickets sold only to foreign visitors.

Rent a car in Lisbon, and you can see most of Portugal in a couple of weeks.

But rent a car in Sydney, and you and your car will be beat if you try to do all of Australia in a month. The continent measures 2,300 miles from east to west and 2,000 miles from north to south--roughly the same size as the continental United States.

The best way to sample the Land Down Under is to buy an airline pass, sold only to foreign visitors. For $484 each, my wife, daughter and I recently got to travel more than 4,000 miles on our Qantas Explorer Pass, from the wild rain forests of Tasmania, to Cairns on the Great Barrier Reef, to Sydney and Melbourne.

Both Qantas and the other major Australian airline company, Ansett, offer passes that cost $484 for four flight segments; up to four additional flights are allowed at a cost of $121 each. The price goes up to $554 for four Qantas flights if any of your flights include the far western port of Perth, the Great Australian Desert sites of Alice Springs or Ayers Rock, or the Great Barrier Reef resort islands of Brampton, Dunk, Great Keppel or Lizard. On Ansett, the $554 fare includes Broome and Port Headlands in Western Australia, and Hayman Island on the Great Barrier Reef.

But even the higher tab is a bargain when you consider that you can go from Sydney to Perth to Alice Springs to the Great Barrier Reef and back to Sydney, nearly 6,000 air miles to some of the most amazing sites in the world, for the same price as a round-trip ticket between Sydney and Perth.

Qantas and Ansett require you to buy the passes before you leave the United States and ask that you set your itinerary before you embark on your first Australian flight. But you can change your schedule as often as you like at no extra charge, provided there’s space on the plane. Qantas’ Explorer Pass is valid to more than 100 cities within Australia; Ansett’s Visit Australia Airpass is good to 24 Australian cities.

A couple of caveats: While we found Qantas personnel quite polite, they weren’t always familiar with the air-pass concept. Getting confirmed seats for each flight often took a little cajoling with the agent over the phone.

Most of our Qantas air miles counted toward our American Airlines frequent flyer account (Qantas miles are also credited to Alaska and Continental’s programs; Ansett miles are good on United’s Mileage Plus program as long as you fly to Australia on a paid United ticket.) For some reason, though, American would not credit our miles in and out of Tasmania. Several calls to the airline produced different answers, most ending with, “That’s just the way it is.”

If your trip to the South Pacific includes time in New Zealand, you have several options.

Both the Qantas and Ansett passes permit travel within New Zealand, as long as you’ve purchased an international ticket that includes travel between Australia and New Zealand. No more than two of the original four flight segments can be within New Zealand, and if your itinerary includes Queenstown, on New Zealand’s South Island, you’ll be charged $554 for the original four flights. Qantas’ South Pacific Airpass allows travel to Australia, New Zealand and Fiji.

The basic Air New Zealand Explorer Pass includes three flights and costs about $262 (actual price varies, depending on the rate of exchange); up to five additional flights can be purchased for about $88 each. The pass is valid for one year. Routing must be confirmed before arrival in New Zealand and cannot be changed, though dates can be changed without penalty. Mount Cook Airline’s Kiwi Air Pass costs $548, starts in Auckland and allows one circular journey around New Zealand, stopping in each city once. The pass is good for 30 consecutive days.

Many other foreign airlines have their own air passes, which must be purchased before you enter the country in question.

Before you buy a pass, figure out how much traveling you want to do and how much individual flights between those destinations would cost. You may spend less by adding those flights to the cost of your international ticket.

The following is a sampling of other air-pass possibilities:

Argentina: Aerolineas Argentinas’ Visit Argentina Pass costs $450 for four segments and $120 each for up to four more segments. The pass is valid for 30 days; mid-trip itinerary changes are $25.

Caribbean: LIAT’s Explorer pass, good for 21 days, costs $199 and allows three stops anywhere LIAT flies except Georgetown, Guyana and Caracas, Venezuela. A more extensive version, the Super Caribbean Explorer pass, allows one month of unlimited stops in one direction for $367.

Chile: Chile, which doesn’t have roads along many Andean mountain stretches, also has an air pass offered by Lan Chile, the country’s major airline. It costs $550 for unlimited flights within 21 days. If you only want to go south or north of Santiago, the pass costs $300. If you want to include the Pacific outpost of Easter Island (2,300 miles west of the South American mainland), the pass goes up to $1,080 for five flights.

Europe: The EuroFlyer Pass lets you buy coupons for flights to more than 100 cities within Europe for $120 each, as long as you fly round trip from the U.S. to Paris on Air France, to Brussels on Sabena, or to Prague on CSA-Czechoslovak Airlines. You must buy at least three coupons and no more than nine. Before departure from the U.S., a cancellation fee of $120 applies; rerouting once travel begins costs $60 per flight segment. South Pacific: Qantas’ Visit South Pacific Airpass allows travel between most of these countries: Australia, Cook Islands, Fiji, New Caledonia, New Zealand, Papua New Guinea, Solomon Islands, Tahiti, Tonga, Vanuatu, Wallis Islands, Futuna and Western Samoa. At least two flight segments must be purchased before arrival in the South Pacific. Cost per segment is $150-$300, depending on where you fly.