You won't see many people promoting this script...

Why?

Because it's free.  Since it's free, there is no affiliate commission to be earned.  The value placed on the script is $197, but right now the only price you'll have to pay is a link back to the coder's site on all your pages.  You may even be able to work out a deal with him if you want to ditch the links ... it never hurts to ask, especially if you're making a killing with all the new traffic you're getting!

I'm testing it out right now, and it really is VERY powerful.  It does exactly what the title of this post implies, and it does a very good job at both.  I'm still finding new ways to use this, and I hope you will too.  (Here's a hint - build a directory for a SMALL, HUNGRY NICHE MARKET.)