XSS and User Modelling

Stumbled across a couple of articles on DeveloperWorks that people might 
be interested in.

First off an article on the basics of preventing cross-site scripting:
(examples in perl rather than php but im sure you'll cope ;-)

http://www-106.ibm.com/developerworks/library/wa-secxss/?ca=dgr-lnxw10PreventXSS

Then there is an article on Web User Modelling in PHP:
(basically tracking what users do and where they go on a site, how long 
they spend there etc...)

https://www6.software.ibm.com/developerworks/education/wa-usermod
(sorry that one needs registration)

some bedside reading there anyway.

miko