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
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.