Very nifty! It looks like not all of their "street view" cameras are mounted on cars. Unfortunately, they didn't choose to move around a lot with them in the sections I watched, just did a panarama from one spot. I would have liked to walk across and look down from that suspension bridge, to see how realistic it felt.
I had some trouble realizing how to investigate the different views. Apparently you have to close the welcome screen, then close the video that follows (either before or after watching it, at your option). I would like to have seen the welcome screen have options to reset it part way through, and some points of reference. Also it would have been nice to have clear navigation options from the beginning. I'm not sure if I understood it well enough to use the tour optimally. I was really impressed with what I saw, anyway.