How to use tags to drive instance parameters in Revit

This Revit Architecture 2009 video tutorial covers how to use tags as drivers for parameters rather than just for display. The idea here is to use “working tags”. The Tags can easily be cleaned up for display on working drawings later, the intent here is to avoid having to go to the properties of an object to change parameters. See how to use tags to drive instance parameters in this intermediate level Revit Architecture tutorial on building a park bench table.
Topics Covered
-Creating shared parameters
-Creating a generic tags
-Tagging shared parameters
-Using tags to modify parameters

Here is a link to the source files on the forum:
http://designreform.net/forum/index.php/topic,729.0.html