The first one is a boon to *nix programmers: how to open a man page from inside vim! Turns out this is rather easy: your vim installation came with the file /usr/share/vim/vim72/ftplugin/man.vim, which defines the command Man (with a capital ‘M’), which you can call like so: :Man _some_manpage_. To make this command available, just add this to your .vimrc:
Now, while editing a C file for instance, you can do a :Man printf and vim will horizontally split the screen, and display the manpage in the upper half. If you’re like me, and prefer to split the screen vertically, do ^Wt^WH.
The second tidbit is about Vim folding. Whatever the fold method used (indent, marker, …), if one is used, when opening a file, all folds present will be collapsed. More often than not, I find this an annoyance, so after setting the indent method, I added another line that expands all the folds, like so (again done in ~/.vimrc):
autocmd BufRead *.* norm zR
The last line expands all folds; the middle line is actually to prevent folds with less than 10 lines (which is fairly common in source code, given that the fold method is indent).