Bright idea

Those who manage computer servers know that you can tell the machine to blink a light for a particular disk or sometimes for a particular controller, so that when you yank the defective item you get the correct one.

I was helping with some cable tracing yesterday.

You are familiar with those LED cable lights that turn from color to color to color.

They'd be an extra-cost item, but imagine a network cable that was twinned with such an LED strand, so that you could tell the server to turn the light on and find out where the cable went.

If that doesn't seem obviously wonderful, look at this and remember that the cable run started out nice and neat, but over the years replacements make it look just a little different.

Of course, by the time you realized that you really needed such an item, it would be too late to install it. There's probably a theorem to prove that whichever cable you really need to trace is going to spend at least part of its length at the bottom of the pile. I can count the exceptions on my thumbs.