(From the thread, compliments of DLF)
I was able to program an additional key on my '98 with only one working key.
From the '98 Owner's Guide:
SECURILOCK ANTI-THEFT SYSTEM
Your vehicle is equipped with a coded-key anti-theft system. Only the correct key will be able to start your vehicle. If your keys are lost or stolen, you must take your vehicle to a Ford/Lincoln-Mercury dealership for re-programming.
Programming additional keys
If you need additional keys electronically coded for your vehicle, spares can be purchased (a maximum of 16 keys can be programmed). To program a new key, perform the following procedure:
1. With the coded key in the ignition, turn the ignition from ON to OFF.
2. Within 15 seconds of turning ignition off, insert the new coded key into the ignition and turn it from OFF to ON or START. If successful, the THEFT indicator light will illuminate for two seconds. Repeat procedure for all new keys.
If key coding fails, the THEFT indicator light will flash.
Coding failure can be caused by any of the following:
The new key was not inserted into the ignition within 15 seconds. 16 keys have already been programmed.
Yea he cut the one I bought from bud a few years ago but then just to be sure he cut another of his and gave it to me. Now I have two spares, as they both worked and two more key fobs. I guess going into the hardware store in uniform helped me