Just as I was about to drop an old 120MB hard drive into the hopper, I remembered that HD motors have big, powerful magnets. Since one can never have too many magnets, I went diving for them. I temporarily forgot about magnets when I spied the motor windings: lots and lots of beauteous magnet wire! OK, we'll save *that*.
The next item destined for the landfill was a large PCB that came out of .... I forget... maybe a commercial piece of exercise equipment (StairMaster?). I'd never noticed the 10 or 15 tiny toroids before then. The PCB stays!
Tonight I'll strip a "new" toroid, wind it with "new" magnet wire (a la bifillar), and see what that puppy does with a white LED.