Yep, that is crazy. He's a good man too. In this video: http://www.youtube.com/watch?v=jjUXiwn9djU He talks about using the hair off the back of a fly to paint with and jokes that he'd never kill the fly, because it might have a family or something.
That is one of the more impressive feats I have ever heard about. Even after viewing multiple websites (including the TED video) about his work, I'm still skeptical in the back of my mind. That's how good his work is!
Appearance, and not authenticity, was his goal. And the illusion of 'train' is excellent.
Well, to be fair I don't know how you could make it truly authentic at the scale without some sort of lithography.
You could probably build a hover train on that scale. But, even classic model trains don't have IC engines so it's a reasonable compromise for most people. The goal is to look like a tiny train / world. Which this does fairly well.
Are there easily accessible motors that could drive a train that small?