Jun 06
Delete lines that contain string:
:g/string/d
Turn on|off line numbering:
:set [nu|nonu]
Number lines (filter the file through a unix command and replace with output):
:%!cat -n
Sort lines:
:%!sort
Sort and uniq:
:%!sort -u
Set textwidth for automatic line-wrapping as you type:
:set textwidth=80
Turn on|off syntax highlighting
:syn [on|off]
Force the filetype for syntax highlighting:
:set filetype=php
Use lighter coloring scheme for a dark background:
:set background=dark

Justin J. Novack