Mine

on $*:TEXT:/^[!@.](brb)/Si:#:{
  if ($readini(Away.ini,-n,Away,$address($nick,2))) { notice $nick You have already been marked away }
  else {
    msg $chan $nick is now away for $iif($2,$2-,No Reason)
    writeini Away.ini Away $address($nick,2) $ctime $iif($2,$2-,No Reason)
  }
}
on $*:TEXT:/^[!@.]back/Si:#:{
  if (!$readini(Away.ini,-n,Away,$address($nick,2))) { notice $nick You have not been marked away yet }
  else {
    msg $chan $nick is now back from $gettok($readini(Away.ini,-n,Away,$address($nick,2)),2-,32) - gone for $duration($calc( $ctime - $gettok($readini(Away.ini,-n,Away,$address($nick,2)),1,32) ))
    remini Away.ini Away $address($nick,2)
  }
}