Howtoforge posted a guide about crating a simple vhost with mod_mysql_vhost on Lighttpd

This guide explains how you can use mod_mysql_vhost to create simple virtual hosts on a lighttpd web server on Debian Squeeze. With mod_mysql_vhost, lighttpd can read the vhost configuration from a MySQL database. Currently, you can store the domain and the document root in the MySQL database which results in very simple virtual hosts. If you need more directives for your vhosts, you'd have to configure them in the global section of lighttpd.conf, which means they'd be valid for all vhosts. Therefore, mod_mysql_vhost is ideal if your vhosts differ only in the domain and document root.

  Creating Simple Virtual Hosts With mod_mysql_vhost On Lighttpd (Debian Squeeze)