Recently, I saw a lot of blog post, forum posts etc on Fuel Dumping. For me it seemed like you can book a flight with high fuel charges, and then add another unrelated leg to the flight that you not plan to use to get rid of the high fuel charges. However, I could not find any concrete explanation on how fuel dumping works.
A summary of fuel dumping and the ethics of it are on My philosophy on Fuel Dumping on
Fuel dumping is a method by which a fuel surcharge on an international fare is removed through the addition of one or more additional unrelated segments. Because of IATA (International Air Transport Association) rules that few people understand completely, the combination of certain flights and carriers causes the fuel surcharge to be all or partially eliminated. Although you still have to pay for the additional segment (called a “3X” or “third strike” because it is the third flight and you “strike” it by not flying) the added cost of a good 3X is much less than the savings of not paying for a fuel surcharge of $300-500.
It's a hugely complex topic to figure out how to do. I've read a lot about it and it still confuses me. However, the best resource I've found is the three part series "An Introduction to Fuel Dumping".
It covers the basics, how to find candidate fares, finding and booking a fare with this method, and advanced strategies, and personally I've found it requires a lot of time, effort and re-reading to even make sense of the article, let alone try it out.