Here is a simple way to enable drupal clean url with Nginx webserver
You need to edit your nginx.conf or vhosts

#pico /usr/local/etc/nginx/nginx.conf

There are so many drupal modules there.
But you just need to installed few modules to help you manage your drupal site.

I personally recommended to use drupal 6 modules below :

Few months ago, i have a problem when i trying to migrate my drupal from old version 5.12 to drupal latest version.
When i migrate from update.php all my website contents was broken which is bad for me since there will be a lot of things to fixed :(

So after reading so many drupal tutorials, i decide to upgrade it again with my own way
below is the tutorial how to upgrade drupal cms from version 5.x to drupal version 6.x

First, you need to backup all your drupal files and drupal db.
Here is my drupal site path /home/sentono/public_html