[westward]

Have you looked at Plover? It's target audience is stenographers, but it can be used by anyone who wants to type at 250 wpm.

http://plover.stenoknight.com/

[0xdeadbeefbabe]

Steno is a great at taking advantage of something humans do well, it might be on the far end of that spectrum. I'd like to see a keyboard that with 100 hours or less of practice would let you type at 100 WPM.