The worst is when you expect a password prompt so you type the password and hit enter, but you mistyped the original command and you end up typing your password in plaintext onto the command line. oops.
If you're using `bash`, A quick remedy for this is:
unset HISTFILE
exit
This prevents `bash` from updating the `~/.bash_history` file on exit with the command you don't want memorialized. (assuming you don't also have some hook that updates your history file after every command)
