the simplest solution i can think of right now (I'm half asleep) is to:
1) pull out your fog light relay (passenger kick panel, black relay in the lower right)
2) pry off the cover of the relay
3) find the actuator arm (should be a copper arm that makes contact once the relay is energized), and bend it enough to make contact with the pad below
4) replace relay cover, and reinstall
your fog lights will always be on while your key is in the 'ON' position. You've basically simulated a stuck relay, and you can always bend back that arm to revert back to stock operation (or plug in a new relay)