Hello,
I hope this is the right place to post my idea.
I'm using xournal to correct CAD Drawings (pdf-format).
The paper format is often A0, A1, ... and to have a look for details So I've to zoom in the drawing, pan it ...
Therfore it would be create to use a http://en.wikipedia.org/wiki/3Dconnexion mouse on the left hand side and a wacom pen on the right hand side.
There is a daemon to use it under linux: http://spacenav.sourceforge.net/

I love xournal - and use it since serveral years .... it's nearly perfect :-)

best wishes

Alexander