[UPHPU] "Dynamic" Drop down menus

[Caleb Call]

What's gong to be the simplest way to create a group of dynamic drop  
down menus?  Basically what I want to be able to do is populate each  
following drop down based on what was selected on the previous drop  
down.  I am helping to put together a section of our intranet at work  
that would have docs depending on their department and what they need  
to know per department.  I'd like to try and not use a database but  
if it's necessary or would make it easier, I could do that.  Any  
suggestions?