This! I, too, strip down discards for parts, and toss 'em in a huge bin. But then I glue 'em together to make sci-fi “art” – Steampunk gizmos that look techie. I can often sell them at Steampunk conventions.
Desktops, monitors, printers and other computer equipment come with detachable power cords. While I’ve discarded a lot of this type of equipment over the years naturally I have saved these power cords in case I need a spare.
[Although almost everyone reading this thread will be shocked to learned I recently threw about 15 of these out–leaving only a half dozen spares.]
I have also thrown away a lot of computer parts I used to save–would you believe I have thrown away floppy drives, parallel printer cables, hard drives under 80GB?
I only do this for items with very wide re-usability. As an example, virtually every computer and a lot of printers and networking gear use the same style of power plug. Ethernet, USB, etc. Wood screws I’ll often save. Scrap lumber too.
Something like machine screws, though: too specific. I need a screw that will exactly match the hole/nut on something else. Coming up with that match means either buying something or having a ridiculously large collection of junk.
Also, things that require a lot of tinkering are out. A vacuum’s electric cord can technically be wired into anything… but I’m not a fan of doing my own wiring. (Besides, how do I know the cord complies to the electrical load of the new project?) As I said, though, scrap lumber is worth keeping because it’s easy to cut down to size.
I do periodically throw things out. For example, I got rid of all my old SCSI connectors and terminators two years ago. And that old 4 GB hard drive? Bye bye.
I used to do this quite a bit. Now I’m downsizing and only save something once in a great while if it seems generally useful.
Hitler?
My then girlfriend (now wife) used to make fun of me for all the random old bits of junk I used to have lying around - mainly computer and car stuff.
Then one day her laptop went bang, leaving her without a computer. Two hours later, I presented her with a fairly outdated, but complete and fully functional desktop computer that I’d Frankensteined together out of those exact random old bits of junk I had lying around. She stopped making fun of me so much after that. 
Computers never get thrown away in our house - if one goes wrong I’ll fix it and throw the faulty part away, if I upgrade I’ll keep the old parts around. Every couple of years, I’ll have a sort out and get rid of the stuff I’ve either got too much of or just know I’ll never use again (10mb/s 4 port ethernet hub? 20gb hard drive? In the bin you go! Starter solenoid for a car I don’t own any more? eBay. PATA ribbon cables? Mmm, might come in handy but I probably don’t need 15 of them…)
I know a lot of this stuff can be replaced cheaply, but it’s often the convenience of it that makes me keep stuff. For example, the other day I was bleeding the brakes on one of my cars and ended up destroying one of the bleed screws. Sure, new ones cost pennies, but that would have meant getting changed, driving out to the nearest place that sells them (about 15 minutes away), buying them, driving home, getting changed and back out to the garage. Probably about an hour lost. As it was, I found a perfectly good used one in my spares drawer. Total time spent? About a minute.
I had a car die and I took it apart and sold a lot of the pieces on eBay. But I have another couple of cars which are the same model, so I also ended up cannibalizing some of the parts for my other cars.
Last summer I was about to leave with my son for his driver’s license road test when I realized that I had not checked the tailights and turn signals of the car we were taking. Sure enough, a couple were out, which is an automatic fail. No time to head over to the auto parts store. But I had a bag of bulbs and fuses from the old car and I found the couple that I needed and popped them in and made it on time.
Having to go to town for a non custom part = FAIL
Working out in the country is like working on a boat, you better have spare right there, in the dirt & grass or in 45 feet of water, well, you get the idea.
Old motorcycles & old cars, going to town accomplishes nothing. Broke down at 40th & Plum means no way to get to the store.
I can’t cut back, either cold turkey or not even trying. It is an addictive thing for me.
Yup. Computer parts, electronic parts, mechanical bits, nice chunks of metal, screws, and so on. I have a big garage and lots of bins.
It’s true that 95% is useless junk. But that last 5% sometimes comes in really, really handy. And I don’t know what that 5% is until I need it.
My husband does this all the time - furniture parts, machine parts (from various things), tool parts - I can’t really say with any certainty because I can’t make heads nor tails out of what actually is in our garage nor do I want to, but I will say this - the parts come in handy more often than not, and especially some of the furniture pieces have become parts of new pieces that he’s built that have turned out beautifully and are now proudly on display and in use in our house. Every so often he goes through the flotsam and jetsam and puts stuff out to be thrown away/junked, but he has a really good handle on it so we’re not at all overwhelmed with “parts”.