UEOI Web Analytic White Paper Series - Integrating WebSphere Portal and Webtrends 

Another thing you are going to want to track are search conversions - what search terms resulted in a click to the page. That can be very challenging with Portal since the urls are encoded.... off hand I would imagine you'd need to use cookies to track what the search terms were etc. without going deeper into the portal code.

Some of these code changes seem rather fragile, for instance looking for html tags like this on the search portlet

document.getElementsByTagName("strong");

Any change to the search results portlet could invalidate this code.

Hopefully in v7 things are better.