The same technique was used later in satellites to map terrain. I had the chance to see an image of the Himalayas, in my Remote Sensing class. You don't use any special glasses and consequently experience minimal eyestrain, even when you view the image for hours. ( This is important if you are scouring the image for some small detail.) And the 3D effect is so much better and lifelike than current 3D in movies. I wonder what it would take to get that kind of experience to devices today.
I have always wondered why 3-d tech is so gimmicky and silly looking. Life is 3-d, and it looks good.
Because when you look around in the "real world" you control the focus and depth. 3D otherwise chooses that for you, so you're stuck being dragged around unnaturally.
I wonder if someone has developed a stereoscope interface to Google Earth?