This is my first post written using an all Dvorak keyboard layout. If you have no idea what I'm talking about, Dvorak is a newer/better keyboard layout compared to good ol' qwerty. I started the switch to Dvorak sometime in late November partly because I had some rsi-type issues because of long hours spent on my laptop keyboard, but mostly because I wanted to learn something new that was not an esoteric programming language.
I cannot elaborate on the reasons to switch to dvorak as well as these guys do If you are remotely interested in switching to dvorak, this is a great (and relatively short) read.
If you do decide to go ahead and take the plunge, this tutorial is awesome. I will strongly recommend doing most, if not all of it to get your fingers used to things.
Finally, one thing I really wanted to do all along is measure how well (or not) I was doing over a period of time. So I used Google Spreadsheets and measured my wpm and error rates using the same measurement tools to track my progress. I used this site (typing the Gettysburg address over and over again) to measure these - its not a good sample for work stuff because its rather thin on the ;s and certainly doesn't include <> and  or /=. The C language and the Gettysburg address don't have much in common it turns out.
Item Numero Uno:
My great hope, when I started this exercise, was that I would be able to prove that learning dvorak does not imply that I couldn't do qwerty. Something along the same lines as learning French isn't going to make you forget English. Bzzzt. The data isn't very good at this point and I'm pretty close to DISproving my hypothesis - assuming you can count my experiences as "proof".
The dvorak error rate has been under 10 for quite a while now and what is most interesting is that it got to under 10 within 2 weeks of starting to learn dvorak. I don't know if this is the strength of the dvorak layout or the power of the human brain to learn something completely different so quickly (it certainly isn't me - I am typically not a fast learner with anything involving motor coordination), regardless, I think the low low error rate is astounding. I am interested to see if the error rate stays down as the WPM goes up (I suspect it will).
One more thing for the (extremely) nerdy: I didn't switch any of my emacs keybindings at all and its not been too bad. Definitely had periods "discovering" some key combinations that I "knew" but it doesn't take too long to adjust.
All in all, I can't wholly recommend or disrecommend dvorak at this point. I have definitely had my share of frustrating moments - typing at 20 WPM is slooooooooow - but then again my rsi hasn't kicked in and I've been hitting the laptop pretty hard. I think I'm on the positive side and am definitely past the point of no return in my conversion, so its unlikely that I'm going back, but I feel that the journey has not been easy and you'll want to be sure about it before diving in.