If you want better shortcut muscle memory, just unplug your mouse for a couple days. Do this once a year or so. You can thank me later.
I've done this a few times when I've needed the space for taking notes. I'm now pretty good at mousing with either hand - but the key part is not making mousing more annoying, like it was the first time I swapped, but rather just making you realise when you're reaching for it. That gives you a chance to consciously think about what you're about to do. And then you have a chance to decide that you're going to figure out how to do it with the keyboard.
System Preferences -> Keyboard -> Keyboard Shortcuts
And change the radio at the bottom to "All controls" under Full Keyboard Access.
In the System Preferences window, you can start typing to select 'Keyboard' (keyboard focus is in the Spotlight menulet).
You can tab to the 'Keyboard' / 'Keyboard Shortcuts' tab bar, then arrow over to 'Keyboard Shortcuts', then tab to the 'Full Keyboard Access' radio buttons. Sadly, these last few steps require that Full Keyboard Access already be turned on! The text below the radio buttons says that you can toggle the setting with CTRL-F7, but that doesn't work for me; I'm not sure if some other keybinding is interfering.
(as root)
# ps axo ucomm | grep -q SecurityAgent && osascript -e 'tell application "SecurityAgent" to activate'Or just hit Control-F7.
Command + first letter button title
will activate that option, with a few caveats - Command-C won't work as Cancel, but Command-. will.
map <up> <nop>
map <down> <nop>
map <left> <nop>
map <right> <nop>
imap <up> <nop>
imap <down> <nop>
imap <left> <nop>
imap <right> <nop>
I use Colemak, so hjkl is very counter-intuitive for me, whereas the arrow keys make sense and aren't /that/ far away.
EDIT: http://news.ycombinator.com/item?id=3684515 has some good explanations. So does anyone have suggestions for non-QWERTY users? remap the keys that are in the HJKL space, leading to a cascade of keys moved around? Deal with the counter-intuitiveness of actually using HJKL?
Even if hjkl is faster, I would be optimising for a case that just doesn't show up that much.
You'll then need to move the insert on left side of cursor, which was i, to h, the key on the left side of your index finger. Reach left to insert left. Easy for muscle memory. With that, both sets of arrowkeys on the keyboard work the same, and you won't need to disable one of them. Normal arrowkey muscle memory, and reach left to insert left. So easy.
Bill Joy was working in an era when keyboards didn't have separate arrowkeys and the ESC key was within easy reach. He wanted it to be as easy as possible to remember lots of different command keys. He used what was printed on his key caps, such as a straight line of arrows on hjkl and various English words such as "yank" in his design. It was a good idea at the time. He also realized that keyboards varied, so he made it all remappable to adapt to future keyboard designs--also a good idea.
But the programmers themselves couldn't adapt. The choices Joy made for that obsolete keyboard were frozen in amber by programmers whose habits were frozen in amber. These days, almost all keyboards have real arrowkeys, and people develop the muscle memory to use them long before they ever hear of vim. Also the ESC key, such a fundamental key, is off in Siberia.
For every vim user with vim habits based on an obsolete keyboard they don't use, there are 10,000 potential vim users with keyboarding habits based on the modern keyboards they DO use. Those 10,000 people use inverted-T arrowkeys, x/c/v as cut, copy, paste, they can't reach their ESC key, etc. Vim was designed to adapt, but old vimmers apparently weren't, so the design features that give vim its power are forever stuck behind arbitrary key layouts optimized for the wrong keyboard.
It makes more sense to remain consistent with existing muscle memory and keyboards, using the inverted-T arrangement ijkl, mapping your left-side insert to the left side key ('h'), and mapping ESC to something easy to reach, such as ';;'. Then, if you ever need to use a non-customized vim, just use the real arrowkeys, which will still feel natural. If you ever need to use another app with a serious vi mode, like zsh, it will be remappable to match your vi. (If it's not a serious vi mode but just a couple of vi-like keyboard shortcuts, either use the arrowkeys or do what we always do, given that every app has its own unique set of keyboard shortcuts: just learn a few new shortcuts for that app.)
It seems like the perfect setup to me. An inverted T would cause you to reposition a finger every time you wanted to change direction. I do that often enough that it doesn't seem very efficient to me. I had some doubts as to whether jkl; would be a better option, but it really does seem more convenient to have the "down" key below your index finger.