Thanks to synergies and global coverage, the world’s three major airline alliances -- oneworld, SkyTeam and Star -- a traveler who wants to take a trip around the world much easier. If you have the time, these airline alliances are ready to help you craft the perfect itinerary on their participating carriers via special sections on their respective websites.

oneworld Explorer offers three, four and six continent journeys with what it says are unique trips thanks to the more than one thousand destinations served by its 15 alliance partners, including American Airlines, British Airways, Cathay Pacific, Qantas, Qatar Airways and TAM.

A four continents itinerary would cover the following cities: Cairns, Brisbane, Kuala Lumpur, Hong Kong, Tokyo, Helsinki, Dusseldorf, London, New York, Toronto, Los Angeles, Sydney and Cairns.

From the main page, you are sent to a separate page to book a round-the-world fare. And of course, there are some rules: you must book your trip at least eight days before departure and complete your journey within 12 months of departure; there must be at least 10 days between your first and last international sector; your journey must include at least three continents and only have one intercontinental departure and arrival in each continent; your itinerary must have less than 16 total segments; you can only go in one direction around the globe and travel through your start city only once; and you can only cross the Atlantic and Pacific Oceans only once.

The SkyTeam alliance, made up of 20 airlines, gives travelers access to a network of 1,064-destinations around the world. network and convenient connectivity between SkyTeam hubs worldwide.

The alliance offers passengers a Round the World planning tool to help them select destinations for an ideal journey. I chose Baltimore, Honolulu, Auckland, Sydney, Kuala Lumpur, Chennai, Istanbul, Copenhagen, Madrid then home to Baltimore.

The alliance has its own rules, including: travel must begin and end in the same country; it must include at least (but not more than) one trans-Atlantic flight, one trans-Pacific flight and one flight between area 2 and area 3; four to 16 segments; reservations required for all flights prior to departure; and between 10 days after first international departure and one year.

And last, but not least, is the Star Alliance. The alliance’s 27 airline members offer 1,316 destinations in 192 countries using a handy too. My itinerary: Baltimore, San Francisco, Tokyo, Beijing, Bangkok, Mumbai, Istanbul, Vienna, Lisbon, Reykjavik, and back to Baltimore. I like how the tool gave me an estimated price ($6,191) for my routing.

The rules are similar to the other alliances: travel must follow one global direction only (East or West) and each traffic conference must be crossed only once: the Atlantic and the Pacific oceans must each be crossed exactly once, and only one crossing between Europe, Africa/Middle East and Asia is allowed; you have to include three or more stopovers in the normal and Business Special Round the World fare, with a maximum of 15 stopovers; for the Special Economy Round the World fare, you have to include between three and five, seven, 10 or 12 stopovers depending on the total mileage of your itinerary; and the minimum stay is 10 days and all travel must be completed within a year after departure.