Mine

on ^*:text:%bwtext:#: {
  haltdef
  var %sym
  echo $chan $timestamp < $+ $nick $+ > $1- $chr(91) $+ $backwards_text($1-) $+ $chr(93)
}

alias backwards_text {
  var %i = 1
  var %txt
  while (%i <= $len($1-)) {
    %txt = %txt $+ $replace($mid($1-,$calc($len($1-)-((%i)-1)),1),$chr(32),$chr(160))
    inc %i
  }

  return %txt
}

alias backwards {
  msg $active  $+ $backwards_text($1-)
}