I recently came across the new BeeRaider keyboard (
http://www.beeraider.com) with that they call a radial layout:

I have no idea what kind of switches they use. I find it hard to believe they could use any standard mechanical stick in that layout.
It's a bit strange that they built what they consider an optimal layout for the main block of keys, but then stuck in the nav block and the number pad block like any full size keyboard.
Regardless of how effective this layout may or may not be, it brings up interesting questions about keyboard layouts. I'm sure there are people on this board that could write books on the subject of which keyboard layout is the best: QWERTY, Dvorak, Colemark, Maltron, Norman, etc. That said, however, those layouts still basically assume the same physical position of the keys. There are a coupe of things that vary, such as staggered vs. ortho-linear, or standard vs. split keyboards, but the layouts themselves don't change with those variations.
As hobbyists, building something without standard switches is not so simple, and would seem to be nearly impossible with mechanical switches. In any case, what do people think of radical layout changes like BeeRaider's 'radial' layout? If there something intrinsically advantageous to current linear layouts? What other radical layout changes have been done in the past? Any theories on what else might work well?