Visualization of Social Concepts Requires Software (Open Source?)

Digging for low cost tools to allow more people in our company to generate better visualization led me to the following tools:

NVU – A Dreamweaver like open source software application
Inkscape – Vector Graphics Tool, also open source, similar to Illustrator
Gimp – graphic editing similar to a photoshop like app (already a Gimp user….)

And in a somewhat unrelated discovery, check out the Visible Human Server for "slices" of the human body.  Awesome for science class!