Alright, here are the most detailed instructions I can give to make your own component cable, elaborated from the first post:
Disclaimer: Do not attempt this if you have never spliced, stripped, cut, or otherwise messed with cabling before. You will probably screw it up, and you won't have ANY working cable, and right now it is IMPOSSIBLE to find it in stores. I take absolutely ZERO responsibility for anything that happens to your cable, wii, equipment or body. This is also not for people who can't bare to be without their Wii for a second, get frustrated easy, cry easily, are PMSing, or retarded.
If you know what you're doing, you can do it in under an hour. If you don't, it'll take you a while. As long as you don't cut or remove anything you shouldnt, you can give up at practically any time, and the composite should still work just fine.
You will need:
A wire stripper/cutter
2 or more large paper clips
Electrical tape/heatshrink
Needle nose pliers, or soldering iron optional
3 spare RCA or Component cables
Balls
First take the grey cover off the composite cable. This is probably the hardest part...you need something very thin and VERY stiff. I ended up just cutting away at the little clips in the front. You want to push the wire through, NOT pull it out. Then get that little black plastic clip out of the way. Also get rid of that little metal thing that bundles the wires.
Take one of the black wires from the composite cable, DO NOT REMOVE IT. Strip it a bit, give yourself an inch or so to work with...it'll be the ground for the rest of the cables.
Grab a spare set of component cables or RCA cables...for 480p, it won't really matter. Cut them off at one end. For each cable, separate the inner insulated wire (positive) from the outer loose wire (ground). Twist the ground wire around to make it easy to work with. Strip some off the ends of each of the positive wires, and twist as well.
For all three of the ground wires from your new cables, splice/solder them into the ground that you stripped away from the nintendo composite cable. Cover this up with tape or heatshrink.
Then take your paper clip. It needs to be somewhat thick: basically, you should be only able to get the paper clip through the pinholes with a little force/jiggling. If it goes right through, its too small, and will be too loose. Cut it apart so you have perfectly straight pieces, at least 1 inch long. Bend one end into a loop.
Then, for each of the three new positive component wires, splice it through the little loop you made, use the pliers to make it as tight as possible, and then cover it with tape/heatshrink. Alternatively, and much better, solder it to the clip.
Keep your Wii off and unplugged, just in case. Connect the cable to the Wii. You can't put the clips in first...they have to go in while the cable is connected. Look at the pinouts from the linked page to double check. Off the top of my head, assuming you are looking at the cable, and the ridge is facing right, on the top row, Y is directly adjacent to the right of the black ground wire, then Pb right next to it, then Pr.
Connect the pin as best you can, make sure it goes in pretty deep and through the hole. Make sure your pin cable is connect to the TV, component is on, and you have it connected to the Y (green) input. Fire up the wii. You may or may not get an image - play with the pin, jiggle/push etc, until you do. You should have a black and white screen, probably still of the safety warning. Get a feel for what you need to do to connect the pins. Once you're confident, take the pin out, and remove the cable. Don't bother with the other two yet, they won't work.
Next, take another paper clip, and cut a long piece of it...2-3 inches. Bend it back on itself so you have a hairpin essentially - the important thing is that both ends are EXACTLY the same length, and EXACTLY level with each other. This is going to be your jumper. You want it to connect pins 8 and 10 to each other. This will prob take a few tries, but do your best. Connect the two pins to each other, connect the Y cable you made before, and fire it up. Go into system settings, and try to set it to 480p. If the option is greyed out, then the two pins arent connected to each other well enough. I dunno if you have to turn the wii on and off over and over again while you try to connect them, I did...and it'll eventually work.
Then once you have it set to 480p, the other two cables, Pb and Pr will be enabled. Connect these exactly as you did the Y cable. First get the Y cable in so you have an image. Then add the other cables until you get half color, then full color. If yours was anything like mine, you'll have a real fun time with this, as jiggling one cable will knock the others out etc. Basically, have your Wii in place exactly where you want it, cause you're probably not moving it after you get it set up right.
Once you got it, leave it alone. You're good to go.