I’ve found my Google Earth interests getting progressively more ornate, from focusing on zero-dimensional experiences to those in three (I’ll explain). At the same time, this trajectory provides one possible taxonomy for Google Earth KML.

Zero dimensions: Static placemarks. First it was all about zooming in on static spots on the globe. Places from childhood, famous places, odd places… many interesting placemarks can be found on the sightseeing sites in the sidebar of this blog.

One Dimension A: Static paths. Pretty soon I discovered the Tour de France routes, and the ability to follow along them.

One Dimension B: Dynamic placemarks — the dimension in question here being time. The best examples include network links for Flickr images, del.icio.us links and Blogwise blogs.

Two dimensions A: Static overlays: For example, detailed images of Area 51 and maps of Easter Island, filling in the blanks where Google Earth goes vague. Also, global population overlays.

[Two dimensions B: Network links to dynamically updated paths? Haven’t seen any examples of this class of creature. One possible example might be the display of the optimal flight routes across the Atlantic given current Gulf Stream conditions. But that’s a bit esoteric, no?]

Three dimensions A: Network links to dynamically updated overlays. Live updated weather maps! Live traffic maps!

Three dimensions B: Static 3D models.

[Four dimensions: Network links to dynamically updated 3D models that change shape and size over time? Haven’t seen any of these either, but perhaps a model of a building site in progress would qualify. Or else colored translucent columns of different sizes across a landscape might be usable as a nifty 3D charting tool of real-time data in several dimensions at once…]