Not sure about wiring the slot itself directly to USB, but the original xbox controllers themselves essentially connect to the console via USB, just with a different plug on the end. That said, if you're still getting some functionality out of it (aside from the aforementioned dead analog) you should be able to just cut off the old xbox plug and wire a USB plug onto it, using the whole thing as your "adapter". The wires will usually be the same color on both the controllers wire and a standard USB cable, though occasionally they will differ, in which case you can refer to this diagram to figure out which wires to connect together. Soldering would be recommended but isn't necessary.
is the xbox gameshark cable anything more then what I'm trying to make?
Not really, all that cable does is provide an interface between the memory card and the program used to copy saves to/from it, which you can do sufficiently just attaching a USB plug to a controller.
"I think that the problem with this video is it is highly derivative of many popular bands within the genre. Although when viewed on its own merits, it does have a deeper groove. However what it has in groove, it lacks in originality. One can't help but be reminded of such bands as Pearl Jam, White Zombie, Suicidal Tendencies and other bands that bear the mantle of so called "Alternative Rock". One is even reminded of Lorie Anderson when she wore curlers. Hehehmhm! This video speaks less to the heart and more to the sphincter. In closing, I think Korn would do well to learn more from -"