Navigate within texts without using arrow keys
I share your preference for keeping the hands in the touch typing position. 

I have a post where I describe my current approach to achieve greater prevalence of vi-style controls on OSX.

To summarise the key points.


Simultaneous vi mode in keyremap4macbook works really well once you get used to it. When you simultaneously press S and D keys vi mode is activated which makes H, J, K, and L function as left, down, up, and right. Holding Down S, D, and F keys makes them function like their function key equivalents. If you are dextrous, you can also pull in the pinky to press shift, and the thumb to press Cmd or Alt. This becomes really useful if you hate having to move your hands from the touch typing position. In the post I also describe a number of other Vim-style keyboard hacks in keyremap4macbook which I tried but ultimately did not persist with given the conflicts with existing keys.
For Chrome there is the Vimium plugin which brings a lot of Vim style keys to the browser.
In my post I also describe the configuration of Vim style text editing for the command-line.