Fantastic thread,
I have borrowed a few of my kids fidget spinners, I think they are cool, I have a plastic one near me currently.
I tempted to get a really decent one but never got round to it. Or make one, in titanium with ceramic bearings, again on the to do list but work got in the way.
I have been known to spin the wheels on a hotwheels car, recently, which I did as a kid, that and I used to keep a high grade titanium M8 bolt and a Titanium m8 nut, in my pocket, very tactical and good play with.
Not sure where it is currently, but I have a few in workshop somewhere safe.