"It's the only way to be sure"
Richard Martin has taken a Hama slide viewer, a small screen and a Raspberry Pi, together with some power and audio circuitry, and created this brilliant Aliens-style movie prop. It allows you to sweep back and forth with a corresponding movement of the display (thanks to a compass sensor) and gives out readings of movement with the dread-inducing sound effect from the film. You can see it in action below and see his code on Github. It was based on this tutorial from Virtual Frontiers.
Wheel of Fortune
Simon Bugler has taken a Raspberry Pi, a Skywriter gesture-detection board and a RasPiO Inspiring circle and driver board and created this quite lovely Wheel of Fortune. By waving a hand over the Skywriter board, he can set the ‘Wheel’ going which is displayed on the circle. The software that he’s written even slows down the Wheel realistically as it comes to a stop. You can see a demo below and read the tutorial of how to make your own here.
Sam VanHook has created this lovely Google Calendar-aware clock out of some birch plywood and then added diffused Neopixels. These Neopixels are lit up by a Raspberry Pi Zero W when Sam has appointments in his Google Calendar. He’s used a CNC router to cut the clock face (although I guess you could do it by hand or with a laser cutter) and the whole build has a lovely feel to it. You can read how he created CalClock over on this Instructable.