tedster - 7:09 am on Sep 6, 2012 (gmt 0)

I use robots.txt to disallow certain URL patterns simply by showing the beginning of the pattern.

So, I can easily exclude various parameters that might lead googlebot into an major duplicate content area, such as:

Disallow /category?sort=

Google has listened to that every time I've used it, and I've used it a LOT.