Great, I just did that and downloaded a couple of them.
A tutorial would be invaluable. Terragen is great from what I hear, but a bit of a bungle for the newbie. Some unfathomable things happen that should be a bit more comprehensible. For instance, I load a GeoTIFF and it just doesn't seem to be "there." I'm almost certain it must be, but the terrain that I see, for example, when looking at the viewer on the Seamless server is just nowhere in my renders or the preview. It's just not visible at all. Of course I'm doing something wrong, and of course I should play with the heightfield shaders, and scaling and so on — but, should I _really_? After getting some real world data? And waiting for renders, adjusting, waiting again?
*shrug*
Julian