I don't think I should learn touch typing to further increase my typing speed. Right now most of the time my pondering over coding problems is limiting my typing speed, not my ability to move my fingers.
But maybe it's worth learning touch typing to reduce the stress on the fingers and be more egonomic?
Traditional touch typing trains you to hold your hands in a consistent position over the keyboard. It's the act of holding your hand in the same position all day--whether that's over a keyboard or around a mouse--that leads to carpal tunnel syndrome.
(For the record: I touch type mostly the way I was taught to. My wrists do occasionally bother me. I'm 24. YMMV.)
That mean my vision is free to concentrate at the screen. That means that my short-term memory don't have to memorize what I am currently seeing at the screen. This means I have more precious short-term memory to do whatever important task I am doing, like, programming.
Subjectively, touch typing is surprisingly comfortable. So even if I'm completely wrong about the above, I still feel better, and that alone is worth the investment.
http://sites.google.com/site/steveyegge2/practicing-programm...
Now, does doubling your typing speed also double your productivity? No, of course not, you spend time thinking, looking through code, reading specs, searching for solutions, compiling, etc. But I don't see how improving your typing speed would not result in at least some productivity gains.
Coincidentally, I'm trying to learn real touch typing as I think it could help me in Vim.
Personally my style is very anti touch, using 2 fingers for the majority of letters, which I don't have to look at the keyboard for but I probably take more glances at it that a touch typist. I think though in being proficient in navigating the symbols on the keyboard mostly makes up for the loss in outright English typing speed.
However, if you catch yourself needing to even just glance at the keyboard while typing basic stuff, you're not a touch-typist, no matter how fast you are.
Many people feel that being fast is good enough. It has been my observation though, that the lag between typos and their fix is considerably shorter (almost instantaneous) for touch-typists (they're looking at the screen as it's happening). Indeed, I'm always a tiny bit annoyed when while sitting next to someone editing code, they accidentally turn on caps and it takes forever for them to realize it (like 10 characters later).