Yeah, I used to have a switch that was wired into the inertia switch for the fuel pump on my old 5.0 Mustang, but for my Contour I took a slightly different approach:
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=picsvids&Number=633790&page=&view=&sb=5&o=&fpart=all&vc=1
I think it will do the trick. Someday I might also put in a switch again when I get time?