That cable is rarely seen now. They're tearing some out of old offices here. But... the stuff is giant Litz wire!

Use it to make loop antennas *OF THE GODS!*

Grab a long run of fifty-pair (100 conductor) and wrap one turn around your house. Solder and heatshrink the cut ends together so every wire connects to the next, but with two ends left over. Now listen to H-mode of VLF "natural radio." Tune it to 60Hz with a huge cap. Can we light an LED? Or perhaps dump some nice filtered sine wattage of 50KHz into it, then charge your electric toothbrush from anywhere in the house. Maybe we could even have "Nikola Tesla" wireless LED lighting, with a resonant pickup coil on each. As long as the JP Morgan next door doesn't realize that "free power" is available. Hmmm, CW baseband 5KHz comms, try it with two coils 100ft apart... ten miles apart?

I used this stuff to make a 200-amp cable, by putting an amp through each conductor of hundred-pair. A bunch of cheap compasses shows the b-field. Twist it into a small 200-amp coil, play with iron nails.

http://amasci.com/exhibits/hiamp.html