Maile Ohye from Google posted a detailed 15 minute video on how to use URL parameters feature in Google Webmaster Tools.

The feature is fairly technical, so Maile who has a gift of explaining technical things is a easy and clear way did a 15 minute video explaining when, why and how you should use this feature within Google Webmaster tools.

Here is the video:

Here is the automated transcript:

Forum discussion at Google+.