You can get pretty darn tiny USB sticks, if you let go of the metal keychain req...

You can get pretty darn tiny USB sticks, if you let go of the metal keychain requirement GP had (some of these work with a thin lanyard, think pocket camera strap).

https://www.amazon.com/SanDisk-Ultra-128GB-Flash-Drive/dp/B0...

USB-C too, though they stick out much more because of the tinier connector: https://www.amazon.com/128GB-PNY-Elite-X-Type-C-Flash/dp/B0D...