Parameter handling now in Google webmaster tools
It can be found under "Site configuration" - "Settings"
This new Parameter handling filter shows the importance Google places on duplicate content and the problems many websites face with regards to displaying the duplicate content accessible via different URLs.
Parameter suggestions on my Smugmug site.
Smugmug is my photo hosting site and it looks like Smugmug has a big problem with duplicate content.This is what Google webmaster tools is saying about my Smugmug site: