Microdrive
en.wikipedia.orgThe MicroDrive is absolutely fascinating and allowed the creation of the highly influential iPod Mini.
I'm not an engineer, but to my layman brain, fitting a spinning hard drive into such a tiny package is the kind of engineering feat that, had it been presented to me as an April Fools' joke, I would have believed it as a funny prank because such a thing is clearly impossible. Like, there's a motor in there? No way.
I mean, this image is obviously photoshopped to shrink it - except that it's not:
https://en.wikipedia.org/wiki/Microdrive#/media/File:Seagate...