Meshlab and Qutemol
I was looking for free software to work with STL-files  used in
rapid prototyping and found Meshlab , which is pretty nice, at
least for viewing and converting meshes from one format to another
(BTW if someone knows of a free software 3D CAD program, please let me
AFAIK, there is nothing else in Debian or Ubuntu for viewing these
files (apart from converting to something like VRML with e.g. admesh),
so packaging Meshlab would be worthwhile. Maybe it could also be used
to visualize some types of medical imaging data.
Meshlab depends on the VCG library , which is also used in a
molecular graphics program Qutemol , all written by the same group.
Qutemol has very impressive graphics output and would be a nice
addition to Debian / Ubuntu as well, but needs modern OpenGL hardware
which I don't have access to at the moment.
I could go on and package Meshlab with a static copy of VCG included,
but if there's someone with suitable hardware, time and interest to
package Qutemol, then maybe VCG should be in a separate package.