A case I designed for a 32GB flash drive as a gift to my little brother, loaded up with indie games and emulators.
Should fit most standard sized flash drives, be sure to measure to make sure though.
Printed at 0.2mm layer height, 0.1% infill, at 30mm/s.
Be sure to drop the flash drive board in as the print head finishes the top few layers of the hole so that it can bridge over the top of it. You shouldn't need any glue to keep it in.