This is a very creative use of Google Maps — all of the pages of a magazine tiled onto the surface of the map, to let you zoom and skim through the entire thing.
The site is Zkimmer. It’s certainly a unique concept, though I have to question the usefulness of it. I think there are a lot of interfaces for reading a magazine that are superior to this. However, I think that this site was probably going for more “unique” than “useful”, which I’d tend to agree with.
One thing that would help is if they enabled the scroll wheel on my mouse. In Google Maps (and many Google Map applications), I can use the scroll wheel to zoom in and out. On this site, it doesn’t work. A concept like this involves a lot of zooming, so this would make it much easier for me to use.
Google Maps Mania has more information.