The user tracking is a good tool, but many times it's very slow recover data from a file flat. In UNED we've developed a tracker to storage the web server information in a database. Another approach is grab the user activity using the views package from many packages.
The tracker has been developed by Félix Hernández del Olmo (http://www.ia.uned.es/~felixh) during his doctoral thesis and he accepts release the source under a GPL license. Now, I'm working with this tool writing a new "user tracking" package based on a database approach, but perhaps the community prefers trace the user activity using the views package, then I would like help in this effort, too.
Any suggestions is welcome.
Regards.