Clockwise: a Lego brick of the most generic size; a 120 minute NTC-120 cassette tape, a micro SD card, and a 36 exposure film cartridge for a Minox camera.
Extremely tiny things amuse me, so when I recently learned about the NT tape format from Sony, I looked on ebay to see if I could find one. About twelve bucks later and I have one. Now I need to get a microdrive to complete the collection.
Update: with microdrive