I always want to see the line-numbers when editing something from VIM, and don't
like having to type :set number each time; thus..
In OSX, edit the vim config file located at:
/usr/share/vim/vimrc
Add the following at the end of the file:
" Custom Config Options
set number
That's it. For Ubuntu 10.10 (Maverick Meerkat), the file is located at:
/etc/vim/vimrc
Same deal there. Hope that saves someone some time.