There is a new program out there called Google SketchUp. Google has entered the 3D business by providing a free program to download that allows users to view or create 3D models which can be uploaded directly to Google for everyone to share. While I'm not particularly fond of the pro-poverty Web 2.0 craze that expects everyone to do all work without any monetary compensation in return, I think there's a lot of potential in this for teachers to make history come alive and for independent students who just want to know about civilizations past.
I was happy to discover that someone had already made a replica (or rather, reconstruction) of the famous Minoan Temple of Knossos on the island of Crete. You can search for more on Google Warehouse.