Weird & Wonderful:
I've saved the best for last -end of the alphabet and all. Also, it's such a broad category that there is absolutely no way I can offer advice on preserving, protecting, or displaying. So I'm taking a break from all that and offering an encyclopedic miscellany of every weird &/or wonderful thing someone collects. (Perhaps not ALL of them, just the ones that tickle my fancy.)
You name it, somebody will collect it. Don't agree? Check out some of these collections and clubs.
For starters, there are Slide Rules. Learned to use these things in high school and one day a rich kid in my class brought his Dad's brand new HP Scientific calculator into physics class. He said it cost about $350 and this was as much as a professional would make in an entire week back in 1973. A year or so later -when I had started college, a simple 4 function job got down to the price that a college student could afford one. My point here is that a slide rule is an oddity to the young'ens and a little piece of nostalgia to the rest of us. And this my friends, is precisely what makes for a good collectable item.
Check out the slide rule collector's club -the Oughtred Society's site, -named after William Oughtred (1574-1660) the inventor.
Or check out this PhD's site on the subject, Eric's Slide Rule Site. And then have a look at this custom mahogany drawer case I made for this guy's slide rule and instrument collection.
Rune' Barf Bag Collection - exquisitely designed, old world craftsmanship abounds here. Come and see what no one is talking about.
Or how about Barbed Wire Collecting for weird collectibles? Fire and the wheel were wonderful inventions in their day, and the steam engine brought about the industrial revolution, but if you are from the Western US, you know that barbed wire did more to settle the west then six-guns. And you damn bet'cha, there are people who collect the stuff. Check out The Devil's Rope Museum.