One of the problems with visualizing the public debt is that it's now beyond human experience. There is nothing at which a human can point and say, "The debt looks like that!"
The amount is simply beyond imagination.
This is my attempt to visualize it: by creating mega-objects in Minecraft. Specifically, I intend to render a number of public debt-related items into Minecraft, all made of gold blocks. The idea is to allow a user to walk up to a gigantic mountain range of gold (or its poly-hedral equivalent).
So far, I'm past the calculations phase and into research. Specifically, I need to quickly create some rather massive items. There's no way I can do this by hand.
As you can see from the debt counter, the amount is increasing rapidly. Hardly surprising, given inflation and the action of compound interest.