I've been using the dxf format to create a mesh that I can view in three dimensions inside of other programs like AutoCad, TrueSpace, and the like. To create terrain (which I have yet to do) I think I would have to create a bitmap from that. Well that's easy enough with Pov-Ray, but I don't know how you guys are going about it. Anyway, I got a pen and pad system over the holidays so I could draw two dimensional maps. The same method I use to create 3D models over 2D plans works for converting drawings to dxf format through a rasterization process. If you have need of such a utility you can find it here:
http://www.wburrows.demon.co.uk/softsoft/wintopo/index-pro.htmI still have a ton of questions about the terrain for AH.