Ask HN: Best way to spend $1k on hardware to impress visitors?

My manager has a budget for "directed playing around", that is, purchasing tech things for us devs to play around with. It doesn't have to result in anything in particular, but it would be nice if we could improve life around the office somehow, and also impress visitors.

The types of hardware we're looking at is definitely RPi and similar, with or without peripherals. But smaller IoT:ey stuff is also interesting.

I'm struggling to think of the killer app, the very cool application we should gather around. Any ideas?

I'm stuck on Raspberry Pi, camera, and using Tensor Flow for something. Probably facial recognition. But it feels _very_ unoriginal.