in reply to Pretty Printing with Data::Dumper

Not exactly what you asked for, but I was reminded of two modules I'd looked at recently that allow one to draw pictures of their data structures (includes links to graphical output).

GraphViz::Data::Structure and GraphViz::Data::Grapher both can output to various formats like .JPG and .PNG, and GraphViz::Data::Structure lets you set horizontal or vertical orientation. Depending on your needs, you might want to give them a try.