Via Jason Calcanis I just found a very thoughtful article by Nicole over at Mahalo with tips to booking cheap airline tickets.
Unless you have a *lot more* time on your hands than I do I think some of these suggestions are basically overkill (priceline and following prices after you book) but she's making several great key points including how important it is to be flexible and to use comparison tools like Orbitz, Y ahoo FareChase, or Kayak.
Here is Nicole's Cheap Airline Ticket article.
I think doing some diligent comparisons on Kayak over a few weeks will usually get you similar results for Airlines in USA. Overseas is much more complex because consolidators can be much cheaper - seek them out for expensive flights.
There is no magic formula - just keep on trucking and you'll find cheap stuff, though not always online.
