Vi Compatible Shell

I like to use zsh as my standard shell for a number of reasons, but I realize the majority of Linux users use bash and Unix users usually use csh or tcsh. Either way, you can allow Vi compatible keybindings in any of these very simply:

in bash:
set -o vi

in zsh, csh, tcsh:
bindkey -v

From there, you can navigate the command-line using Vi key bindings. You can also use most common motions and operators to edit your commands.