Recently a couple people expressed interest in seeing a write-up on how I used the defroster switch to turn on my fog lights, so I went ahead and took some pictures of my stuff. Here's how I did it:
1. First get a defrost switch if you don't have one, as well as the wiring harness plug if possible. I got my switch, switch panel, and plug from Doug at Fiero Warehouse.
2. Pop the switch rocker (the gray plastic button part) off of the switch itself by prying the two sides off one at a time. This is easier said than done, but if you use a small pick or flathead screwdriver to pry one side up and hold it with your finger while you pry the other side, it comes off pretty easy.
3. The defroster switch is intended to be a momentary switch; it accomplishes this by using a spring fixed into the switch that pushes in both directions. In order to allow the relay to stay on, I removed the spring and bent the top side over. This allows the switch to stay on when you push the top, but the bottom still uses the spring, as shown here. BEWARE! The wiring method I used will blow the fuse (short circuit) if you push the switch on the bottom side. You can add a stop for the switch (glue something in there) relatively easy to ensure this won't happen. I just know not to push on the switch, and since the spring is installed one one side still it keeps me from going too far when I turn the lights off. It is entirely possible that with a different wiring method you can alleviate the problem, but this was the best I could come up with when I did it.
4. The wiring is pretty straightforward, but just to make things as easy as possible, I documented the splicing necessary. The wires that I spliced into are for the rear decklid release; if you don't have a power decklid release, then I'm afraid you'll have to find your own wires.
I used butt splices; you can see one of mine is a posi-lock connector, which screws together. I ran out of butt splices and had some posi-locks laying around...the posi-locks are expensive (about 50 cents a piece) but they're awesome! Splice the following wires together as shown here:
Defroster Plug ID - Defroster Color - Decklid Color (Purpose)
D - Black - Black (Ground)
B - Lt. Blue - Orange/Purple (Battery +)
A - Pink/Purple - Relay Wire (Switched power for relay)
P - Tan - Tan/Black (Running Lights +)
C - Purple/White - Relay Wire (Indicator light)
Note that Pin C and A splice together into the relay trigger wire. When the defrost switch is turned on, it sends power out of pin A that goes through pin C and the relay to turn them both on. You will need to run a trigger wire to your relay on your own, wherever it may be. There are a million different ways to do this depending on how well you want to hide it and how hard you want to work.
For those of you that aren't fortunate enough to get the plug that has the identification letters, you can see a pinout for the switch here.
5. The relay needs wired next. The trigger wire (coming from pin A) is not intended for supplying power for the accessories on the relay, it simply tells the relay to turn on. On my application I used a standard four wire relay (power, ground, switched power, trigger). I supplied power from the stock wiring harness that goes to the front of the car. Using a voltmeter I probed around and found a wire that had constant power. I found a large red wire in the loom by the brake master cylinder, as shown here and spliced into it.
Now we have power and a switched input, still need to ground it and send power out. I mounted my relay on the hood prop bracket using the existing nut and bolt by boring the attachment hole in the relay larger. I then made a short wire to run from the ground terminal on the relay and go under the attachment nut, providing the ground.
Lastly, route the power out from the relay to your accessories. I spliced two wires together and ran them to my foglights in the front. You can see my relay and wire routing here. The wiring to the fog lights runs through a pre-existing hole that used to have a plug in it.
Words of wisdom: Don't be like me...solder your wires instead of splicing them and use heatshrink over that. If I had the tools to do it, that's how I'd do it. Also, anytime you run wiring through sheet metal make SURE that it won't wear and contact the wire against the chassis. I use corrugated sheathing or rubber hose to protect my wiring.
I think that covers everything. Let me know if you have any questions, although I doubt there are many left to answer! 
By the way, this relay setup can be used to turn anything on and off, don't limit yourself to foglights!
In case you're wondering why I didn't just use a universal switch, I wanted the switch to look like it belonged there. I also like how it lights up with the running lights and indicates when it is on. Oh, and I paid about the same for the switch/panel/plug that a switch costs...thanks Doug. 
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Bryce
