Originally Posted by
tornado163
If I'm paying for it, I'll just buy the cheaper round trip ticket and then "forget" to show up to the airport for the return journey.
This is not a good idea. If you book a return/multi destination flight you must show up for both legs. If you don't there are penalties that the airline will charge you for, as in effect you are bypassing their fares to get a cheaper one way.
Also I have read that the airline can ban you from flying with them again. Such is the crazy world of airline tickets pricing!