Re:Fighting the Last War--Muskets are Out (Score 1)

Autodesk does sell a 3D parametric solid model design package: Inventor. It's a low-mid level solution with a steadily growing range of functions and user base. Similar to Solidworks, though generally less well regarded, Inventor is extremely easy to learn, with a pretty intuitive interface and feature set.

I've been using Inventor professionally for about four years and have taught it to high school students whom I mentor in the FIRST Robotics Competition. You can see some of their award-winning work http://www.cybersonics.org/cybersonics/awardentrie s/2006/inventor2006.asp/here.