I'm looking for script that does this..

1) simple yet secure user registration
2) users can submit url/descriptions (admin validates or not, does not matter)
3) click hits / dates / rating
4) comments (support anonymous/unregistered users)
5) PHP/MySQL backend
6) Categories
7) Template driven
8) Opensource - Free - $0

You can try the excisting content managment systems. But if you want your very own script... then i think its going to take some time...