Thread reminds me I need to buy flash drives in bulk. I lose and give away more than a few over time. Usually I have one for a bunch of portable apps (mostly from PortableApps), one for live linux/install, a Windows 10 install, a few with encrypted cold storage wallets, one for document/file backup, and a few for transferring files.
I've never taken to using a flash drive on a keychain, but if anyone knows of a really nice USB 3.0/3.1 one that's nigh indestructible (the metal encased ones are decent otherwise) with 64GB+ let me know.