Having looked at LinkPattern I believe this ShowE action is tied to a perl script somewhere? If so, then the number of possible 'Show Actions' is only limited by the number of available perls scripts...?
Also of note of in the LinkPattern was the use of icons, I believe it was a folder icon. Icons for UmlArtifacts, pictures, links, etc could be applied in the TouchGraphWikiBrowser. Better yet, let the user develop their own compliant templates. The shape of nodes 'could be' easily controlled with an xml based coordinate system like SVG.
Again the question of display options comes to question. My absolute favorite is an xml format for the templates. I'm specifically thinking about xybrix at www.jbrix.org. The templating engine is xml based and generates xml output...great for distributing templating systems and creating new ones. --Dennis Daniels