PHP and Mysql graphing

I have had two hobby sites up for a while one here and the other here, both devoted to the Massive multiplayer online RPG Dark Ages of Camelot (DAoC). These games have guilds (similar to a team) and classes (which are the types of characters you can create). One site is for a Guild on the server I made my characters on, and the other site is devoted to one particular class (The Cabalist) which happens to be the one I initially picked when I started to play the game. The class site has been relatively popular, garnering around 200k page views in the month of August. Like Ultima Online and Everquest, DAoC boasts thousands of subscribers worldwide (they say 250k as of Sept, 2002).

I managed to find an excuse to experiment with some interesting technology for the sites, including PHP, Mysql, xml, phpBB2, phpWebsite and phpNuke among others. Several months back i wrote a script that began to pull the number of active users on a regular interval from an xml feed provide by the publisher of DAoC. I use this data to create a graph of daily user activity using a php graphing library called phplot that wraps support for GD a c language open source graphics display library. Although the program appears to be an image (as least that is what's returned to your browser) it's actually a php script that queries the database and returns the plotted information for that day. The program takes a few of paramaters (daocdate, width and height) in case you're interested in playing with it.