I love how this boombox (called HiddenRadio) uses the “least” amount of user interface. The entire product is the UI!
From MocoLoco : “The product attempts to be silent both visually and functionally by having the cap in the downward position. By lifting up the cap the user proportionally increases the volume. The further the cap goes up the louder the sound gets. To tune the radio you simply rotate the cap and receive feedback of tuning quality via the LED on the front.”
What other products have you seen designed this way?