There are lots and lots of other people who advocate buying your plane tickets as you go – and I can understand that. Sort of. But as we aren’t going that route, I’ll go ahead and let them talk about the merits of “spontaneity” and “flexibility” (not that there’s anything wrong with being spontaneous, it’s just that the closest I can manage to come to that is “planned spontaneity”). In this section, I’ll only relate our experience, which was buying a RTW ticket from OneWorld alliance.
We chose to buy round-the-world (RTW) tickets instead of buying as we go or buying open-jaw tickets. There are a few different airline alliances you can buy a RTW ticket from. We chose OneWorld (Star Alliance is the biggest; you can read about them and others here) mainly because they offer a ticket based on continents visited, rather than miles traveled, and they have a fairly expansive network. All other RTW tickets (that I know of) price their tickets by miles traveled, which can make it difficult to zigzag between the northern and southern hemispheres and stay within your mileage restriction. For example, you can buy a Star Alliance RTW ticket with 29,000 miles, 34,000 miles or 39,000 miles. Just to give a reference, the circumference of the earth is a little under 25,000 miles. With the routes Kevin and I were thinking of, it made a lot more sense (and it was cheaper as well) to buy a 5-continent ticket (they also sell 4-continent and 6-continent tickets) from OneWorld instead, skipping North America (they don’t fly to Antarctica).
The way our ticket works is this: you plan a route, using the cities that your particular airline alliance flies to. You are limited to 16 stops, four stops max per continent. You must cross the Atlantic and Pacific Oceans exactly once each. I don’t see what other way there is to go around the world, but for whatever reason that’s listed as one of the rules. There are lots of other rules, but you get the idea. The good thing about the RTW ticket is that you can leave all your flight dates (except the first) open-ended, so (theoretically) if you decide to stay somewhere a bit longer than you first intended, you just call up American Airlines and ask them to put you on a flight later that week or later that month, no charge. In practice, this can be easy or difficult, depending on what particular flight you’re trying to change. I would advise that when you book your ticket, you go ahead and give them some dates, just so you have something. As we learned when trying to change the dates for our flight from Hong Kong to Kathmandu and back, some flights really do get booked up 6 months in advance. Another one that booked up quickly was the leg from Auckland to Chile. So just make sure you don’t wait until the last minute to get the dates for your flights!
We decided to buy our RTW tickets starting in London (in conjunction with a one-way ticket to London) because it cut out a continent, which saved us money – and, for whatever reason, the tickets are cheaper if you buy your ticket in the UK ($2,500ish, depending on the exchange rate, from the UK v. $4,590 from the US for the 5-continent ticket). So depending on where you’re from, it may or may not make sense to actually start your RTW ticket in your home country. I’ve also heard that the tickets are relatively cheap if you buy them from Australia.
The actual process of buying the tickets turned out to be a lot more difficult than I originally thought, until I figured out one important thing: not all of the ticketing agents know all of the rules and some of the ticketing agents make up rules. So if one disagrees with you and tries to tell you that you “have to fly American on one of these flights, or you can’t book it with us” or that you “have to call British Airways, since they’re the carrier of your first leg ” or that you “have to pay the higher fare of the UK and US fares,” don’t listen. Just thank them politely, hang up, wait two minutes and call back. Trust me on this one. I finally figured this out after a few hours on hold and some, shall we say, “spirited debate” with various ticketing agents.
Also, I stumbled across a very helpful message board on flyer talk that goes into far more detail than I have here. I think I actually read through the entire forum, though not all at once.