e-ink keyboard changes for every purpose

I've been into old-fashioned mechanical keyboards lately; Sonder's e-ink model promises to bring the fetish into the 21st century. Each key is both mechanical and a tiny e-Ink display that can change on a per-application basis.

The Sonder Keyboard combines a sleek new design with a built-in rechargeable battery and enhanced key features. With an improved mechanical mechanism beneath each key for increased stability, as well as optimized key travel and a lower profile, the Sonder Keyboard provides a remarkably comfortable and precise typing experience. It pairs automatically with your Mac, so you can get to work right away. And the battery is incredibly long-lasting - it will power your keyboard for about a month or more between charges.

The styling is minimal and Apple-oriented. Sonder's keyboard uses Bluetooth, but comes with USB and a lightning port too. It's $200, which seems reasonable for such a specialized device: compare to Art Lebedev's Optimus Popularis color LED model, still a pricey curiosity at $1500.