What I am about to propose is obviously not in the spirit of the flat tire rule but I'll ask it anyway.
Say there are 2 flights (e.g. SFO -> LAS 1/16/2010)
Flight 1: $39 (takes 2 hours with 1 stop)
Flight 2: $80 (takes 1 hour and is direct)
Question #1: Can you book flight #1, miss it, and then take flight #2 without paying extra fees?
Question #2: Assuming that Q1 is "yes". Can you book a ticket on both flight 1 and flight 2, miss flight 1, go standby on flight 2, and if you get on via standby, use your flight 1 ticket and get $80 credit for a future flight. If you do not get on via standby, use your $80 ticket confirmed and get $39 as credit for a future flight.
It's a slow night so I figured I'd waste some time speculating...
Rock.