Memory stick cap
I still have the cap of my USB memory stick. But I will probably lose it quite soon.
At least since the Duofold from 1921, pen caps have been parked at the other end of the pen when not in use.
Moving that idea to the memory stick should be quite a nobrainer? Or is someone sitting on a U.S.patent for "Structural adaption of electronic computer memory stick to prevent accidential loss of protective connector cover"?
I think that if you finish using a USB stick, it should be removed from the computer, and it should be made a habit to put the cap back on the USB stick when the stick is not connected to anything.
Also, I think that, if possible, if you plug the USB stick into a computer, try to place the cap on top of the usb stick. So when it is time to disconnect your usb stick from the computer, then at least the cap is there, resting on the surface (or side) of your usb stick.