md5 is good for login procedures. The security I'm talking about is more evident with an example.

Let's say I have a bot that keeps the user accounts in a ini file (accounts.ini), like this:

[users]
qwerty=6f1ed002ab5595859014ebf0951522d9
vexx0r=4eb20288afaed97e82bde371260db8d8
foo=2c23312e834c436c527bbdc30050843e

To log in to the bot, I'd type: /msg <botnick> login qwerty <mypassword>
To make sure it is me, the bot would have somewhere in the script:
Code:
on 1:text:login *:?:{
  if ($md5($3) == $readini(accounts.ini,users,$2)) {
    .notice $nick User $2 authenticated
    &lt;other commands&gt;
  }
  else {
    .notice $nick Invalid password for user $2
  }
}
This way, the actual passwords are not stored anywhere, so a malicious person who would gain access to my hard drive would have no way to find those passwords, neither by looking at accounts.ini, nor by looking at the script. Even if he obtained the md5 values, they would be useless to him.

/.timerQ 1 0 echo /.timerQ 1 0 $timer(Q).com