http://colemak.com/
I've been just getting started with it -- I've only just got past the home row, but I like it so far. Some of the more significant differences are removal of one or two Dvorak key placement warts, rearrangement so that the left hand does a bit more work, and as a bonus, fewer changes over the QWERTY layout so that it's easier to learn. The latter seems to have been achieved at no significant cost in finger efficiency -- most of the keys that don't move were either already in good positions or were on the bottom row. The Dvorak-Colemak improvement is certainly far smaller than the QWERTY-Dvorak improvement, and there are design trade-offs to be selected, but I like most of the decisions Mr. Coleman has made.
I've always been reluctant to switch to Dvorak because it seemed to me that it wasn't based on a very thorough rational optimisation. If I'm going to go to all that effort of learning a new keyboard layout, I want it to be pretty close to optimal for me.
As a fairly quick QWERTY typist (94wpm is my record on typeracer.com on a normal keyboard -- great fun, BTW), I like the learning advantage over Dvorak, and the combination of people's reports of reduced finger pain and the removal of my doubt over the rationality of the Dvorak design has tipped the balance for me.
Why not give it a go? If we learn at the same time we could get a fingerfans Colemark typeracer.com competition going
