I've been using Vim for about a year now, and am pretty much addicted. Once I reached a certain level of proficiency, no other editor seems to be even close. The keys are very intuitive to me now, as is modal editing.
Of course, there is a problem when I have to type in other programs. For example, in OpenOffice, I routinely hit j a few times, and am surprised when that letter actually pops into the screen instead of moving the cursor around.
To overcome this, I've been messing around with ways to make Vim more friendly to general writing. Here's what I've done or found:
Autocorrect
This section outlines my major actual contribution. The rest are just tips. Autocorrect is a key feature of almost any word processing program, and it's tough to do by default in vim. When you type 'teh' and then have to go back and fix it, you are much less efficient. Vim has the concept of abbreviations, where you can map one word to another.