For a while now I am typing using solely the Dvorak keyboard layout. I roughly estimate it has been 4 or 5 months now - with the first month being a pain in the ass because i had to relearn typing pretty much from scratch - but now my typing speed is starting to exceed what it used to be in querty, and I still have much headroom to improve.
For those who have no clue what I'm talking about: think for 30 seconds which characters you type the most and which the least (eg: which characters occur the most/least in the language you type?).
Ok you got them? Now look at your keyboard and spot where these characters are. Now consider where your fingers are most of the time (if you've never learned to type: the 'base position' for your fingers is on the middle row). Notice anything strange?
Now how take a look at this picture:
Definitely quite unconventional, but doesn't it make sense?
Dvoraks benefits are both technical (faster typing speed) and physical (less strain on your fingers, less chance for injuries such as rsi)
If you would like more information, I highly recommend dvzine.org. They have a web comic that tells you all you want to know and helps you start using Dvorak
Sure, learning a new keyboard layout is not easy. The first weeks are a pain. And it takes a few months to get back up to speed. But I'm 23 years old and I hope I will be typing for about 50 more years. Considering that I find it well worth switching!