I have looked at this directory script, and it look REALLY GREAT! I get so excited about thinking of implementing it in my website!! However, I thought I'd ask the experts here what their opinions are regarding this software. Also, are there any other things like this (either as downloadable scripts or hosted) that I can compare it to?

Are you referrring to Links SQL (from gossamer-threads)? Coincidently, I'm looking into this product as well for one of our sites. The main reason why I would pick it over other products is that it supports both dynamic and static pages modes.

Silly me...I forgot to include a URL! The software I am thinking of is located at http://www.in-link.net . They have a functional user and admin demo there, too.