From that kind of stuff, you can get little magnets from the voice coil focusing mechanisms of CD and DVD drives, and their laser diodes, big magnets from HDD seek voice coils, lovely 6 and 8mm bars and from printer carriages, with their bushes, lots of steppers, infinite amounts of copper wire from coils, opto-isolators, opto-interrupters, mechanical limit switches, bearings, LEDs with PCB mounts and so on. From PSUs you can get nice ferrite cores for signal and power (and art projects), sometimes FETs, definitely some beefy diodes and heat sinks. Fans are quiet DC motors with wings that can be cut off. It's a paradise for tinkering.
Or you can get $10 on ebay.