Are you noticeably faster on Dvorak? Do you feel learning Dvorak slowed down your Qwerty typing?
No to both by my estimate, but Dvorak does feel (faster, more fluid, smooth). I'm pretty sure that individual dexterity and experience affect (Edit: optimal) typing speed much more than the keyboard layout.
I taught myself Dvorak back in high school with casual practice one summer (possibly a bit longer.) I had minor recurring problems toggling between Dvorak and Qwerty in the classroom for a decent portion of the following school term. So I wouldn't recommend switching layouts to everyone, especially if they're already fluent on Qwerty and can't afford the temporary drop in speed/accuracy.
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.