This is a really neat modification to zen cart that will break down the attributes VALUES that you see by the attribute NAME when you set up attributes for a product.  So, if you have attributes like - size, color... etc.  when you click on the option name size... it will only display sizes that you have entered as option values.

You can also select several option values at the same time instead of adding each one separately.

Zen Cart Version 1.3.9

NOTE:  This module is incorporated into Zen Cart 1.5.0 and above already.