Persistent undo is my favorite new feature. The ability to close vim, reopen a file later, and then have all of the undo history still available is awesome. (Alternatively, I used to suspend vim instead of actually quit.)<p>To turn on persistent undo, I created a new directory called ~/.undo to store all of the undo history so that my working directories wouldn't get cluttered.
Then in .vimrc, I add:<p><pre><code> set undofile
set undodir=~/.undo</code></pre>