Thank you for your replies, however, "squash" is not really what I'm looking for. While I like to think that I'm in the business of "faking it", I'm really in the business of doing what my clients ask for to the best of my ability, and in this case they want two containers of exactly the same shape and relative dimension, with the size of each dictated by the volume of the container. I apologize if that wasn't clear in my earlier post. This is not an "entertainment" job - it's a design job.
Anyway, I figured out a workaround and thought I'd post it for anyone who is interested.
I created my container and froze all the transforms. Then I created a new attribute for the container and called it "volume". Then I wrote a simple expression for the value of the volume attribute - "container.volume = container.sy*container.sx*container.sz". Now I can manually scale my model until the volume value is correct.
There's probably a better way to do this, but it works for what I'm trying to do.
