I'll add a few as I go along. This page has a utility listed that I use everyday (dem2pov), but there be more there that one of you could use. The advantage so far is that Pov will generate any output size I require.
http://www.terrainmap.comUsers of TrueSpace might want to check this out. It takes a black and white height map and generates a 3D mesh for use in TS.
http://www.ryusoftware.com/Thhis program does basically the same thing, but allows for output back to Pov-Ray and a few manipulations I appreciate. Plus, the source code in Visual Basic is available, so someone might make a few enhancements for AH if they were so inclined.
http://www.renderology.com/terrain_forge.asp
