I know you've seen tons of these scripts, but I don't care. :<

This one's mine.

Just add it to your bot, and get it rolling.

Say "set greeting Blah" to set your greeting, and say "set greeting chans #chan1 #chan2 etc" to set the channels you'll be greeted in. ;>

Also, Eugene helped me make this a bit better than it was originally. Just giving him imagination credit. ;P

on *:text:*:#: {
  if ($1-2 = set greeting) {
    if ($3 = chans) {
      set %greet.chans. [ $+ [ $nick ] ] $4-
    }
    else {
      set %greet. [ $+ [ $nick ] ] $3-
      msg $chan Set Chan Greeting For $nick To $3-
    }
  }
}
on *:join:#: {
  if (%greet. [ $+ [ $nick ] ]) && ($istok(%greet.chans. [ $+ [ $nick ] ],$chan,32)) {
    msg $chan %greet. [ $+ [ $nick ] ]
  }
  else {
    if (%greet. [ $+ [ $nick ] ]) { halt }
    else {
      msg $chan $nick $+ , You need to set a channel greet message. "Set greeting Blah Blah Blah"
      msg $chan $nick $+ , You can also specify which rooms to set your greeting in "Set greeting chans #chan1 #chan2 #chan3"
    }
  }
}