A holder for pens and pencils, a phone, USB sticks and SD cards. Can be folded and fitted into your pocket and has a small enough footprint to go on any desk.
Can be printed in PLA, ABS, etc., and does NOT need supporting material, nor any kind of post-processing to work properly.
After 3D-printed, you just snap tiny, pre-made supports within the hinges and it should all work just fine.