Download Project Miller from Autodesk – It basically gives you a visual demo of what the 3d printing process will look like for a given model.  You can animate, cut sections, re-surface and re-mesh your model.

Video:

Whole article:
Stop Wasting Filament! Autodesk’s ‘Project Miller’ Utility Offers 3D Print Simulation and Previews

Heads-up:

Looks like the BIM (model) of the Earth is going to be built by computers, not people:
Google is using a new technology to automatically generate  3D buildings from 45-degree angle aerial photography made by overlapping passes of aircraft. Each airplane has five cameras: four that point at 45 degrees, and one that points down.

Read more at:
Here’s why Google got rid of SketchUp – WorldCAD Access