3D Drape
This is one of the first cool things I've done in GRASS. I know it's pretty simple, but I was happy just to get some data on the monitor! :) This is just an image of the elevation.dem from the spearfish tutorial dataset draped onto itself. I left most of the settings as default, as it tended to look worse the more I played with it.

Photo album generated by album from Dave's MarginalHacks on Fri Oct 3 23:38:49 2003