Hey, want to try this yourself?
We have created a number of step-by-step instructions for constructing some of the more challenging elements depicted in The Plan of Chicago. We also offer instructions for importing SketchUp files in Google Earth, and instructions on how to create image overlays for Google Earth, as the VBI has done with various Plan map images.
Additionally, Google provides a number of online instructions and SketchUp (http://sketchup.google.com/training/) and Google Earth (http://earth.google.com/support/).
Special thanks go to Chris Cronin and Mike Brightman of Google for their training assistance.