Dvorak
Never thought it would happen, but I finally switched to the Dvorak keyboard layout. I've been wanting to switch for years, but there is never a good time for a programmer to have to re-learn how to type.
It wasn't nearly as bad as I expected. For a few days, it was utterly frustrating not to be able to communicate with a computer. The sacred bond between a developer and his tools had been broken. Oh, and I switched on a writing day. Probably not the smartest idea, but whatever.
I've been at it for about 2.5 weeks, and I'm at maybe 80% of my QWERTY speed. It's true what they say -- Dvorak is a lot more comfortable, and I didn't even have RSI symptoms before. August Dvorak, my future tendons thank you.
The worst part is retraining my vi fingers. Years of muscle memory obliterated.