The Virtual Reality Modeling Language (VRML) is the 3D equivalent of
HTML, allowing Internet distribution of interactive 3D geometries. It
requires special browser plug-ins, of which there are many to choose
from.
Browsers and software:
CosmoPlayer
(my favorite, works well in Netscape 4.5+)
Wyoming
topography/geology: this map-server lets you investigate any
part of the state you're interested in. Click on the "3D"
button in the central frame