I just saw this BTC keyboard on ebay:
Probably some kind of rubber dome, but I quite like the layout as something that’s very easy to adapt to for someone used to a standard IBM/ANSI/QWERTY keyboard, but with some improvements made:
- additional hand separation
- split spacebar with "erase-ease" (use one thumb for space and the other for backspace)
- arrow keys on both hands
- alt and windows keys very easy to reach with the thumbs on both sides (or with middle/ring fingers)
Not perfect, but interesting.