in reply to Inspection/Introspection
But I was moved to check again since I remember finding (and I think mentioning on PM, somewhere..) someone who had done a cool demonstration of graphing of his perl program at runtime. I couldn't find it but think this is probably GraphViz..
Answer: Generate UML from Perl code? includes four responses including autodia.
Generate a Graph-ical call tree for your *.pm perl modules uses graphviz at AT&T.
An article at DDJ about using graphviz.
cpan search for graphviz which showed me some other things like GraphViz::ISA and Joe McMahon's site on GraphViz::Data::Structure
Hope this helps.