I've been experimenting with Papervision3D in order to make a 3D version of our campus map. On of our artists has worked up an extremely detailed map in Google Sketchup. I've rebuilt the model in Sketchup using texture maps so that its around 1000 triangles and is to scale in Google Earth. Sketchup allows exporting to Collada files (which it uses in it's own files for Google Earth) and Papervision will parse Collada. Here's the result:
I have not finished texturing the entire model, so there are some plain yellow walls.
UPDATE: I've also added a driving mode!