The kind of person you probably are if you are reading Less Wrong spends a remarkable fraction of the day typing at a computer. As such, even a small increase in typing speed and skill can save you huge amount of time and effort.
This is a highly dubious claim. I (occupations: software engineer, student (CS major)) spend a remarkable fraction of the day at a computer... but do I spend most of that typing? I do not. I'm doing more typing right now, writing this comment, than I do in a much larger period of doing actual work. Even if you only look at the time I spend actively coding (rather than reading documentation / literature, thinking about a problem, debugging, tinkering, etc.) that's still not mostly typing.
Furthermore, citation needed on the claim that touch-typing, as opposed to the way I type now, will save a "huge amount of time and effort".
It is just as easy or easier to learn a better layout (like Dvorak or Colemak), which also will give you a bigger boost to your typing speed and efficiency.
So very citation needed on this one. (Counter-citation: http://www.utdallas.edu/~liebowit/keys1.html.)
After having finished the basic course in Dvorak and touch typing for a few weeks now, here is an update on my results: I spent a total of 30 hours learning to touch type, but even once I could touch type properly, I was still really slow, at about 20 wpm immediately after finishing the lessons, half of my original speed. Ten days later, after forcing myself to avoid the QWERTY layout which resulted in some inconvenience, in particular with keyboard shortcuts, I am now typing at about 30 wpm in Dvorak, which is still significantly slower than my previous, ...
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.