Cables for ski lifts are spliced by untwisting the ends and then meshing the two ends together so that they are intertwined. The spliced area ends up being quite long, maybe 50 feet or more, to spread out the forces. When they are done, you can barely see where the splice is. There are only a handful of people who can do it, so their services are pricey. I don't see why you couldn't use the same technique to splice your shift cable, untwisting maybe 4-6 inches and meshing the two sides together. You could even back it up with some solder for extra insurance. I am not so sure this would work on a brake cable, though, and as cheap as they are, why take the chance?