Inspired by this guy, I decided to make an analog handheld noisemaker based on thousands of tiny grains hitting a microphone element. Nothing too special here, just an amplifier and an LED-blinker. The circuit is triggered by two tilt-switches that activate when the device is upright.
I stained and carved out a wooden craft box to fit my nefarious design, and carefully superglued two piezo pickups and red LEDs into a 30-second game timer I got from the Dungeons and Dragons Store!!!
Getting everything to fit was absolutely the hardest part. That strip of electrical tape across the speaker is a gimmick to reduce most of the feedback. The only way to really kill ALL that close-proximity feedback is... video editing. So it's sort of a challenging piece. Maybe a game! There's a narrow angle where it won't shriek at you.