Any hints or suggestions would be appreciated. 

Thanks  ~Jerry / leather-guy

Well, for line-art, you could load up your art into Photoshop and export it as an Adobe Illustrator file. Then, load that into any 3D app that accepts .ai file formats. I use Adobe CS 2... which is ancient. The newer suite has 3D applications, so it could probably pump out a bas relief of your art. If not, then you'll have to export it as greyscale and use a 3D program that will apply that greyscale image and use it to create actual geometry.

Now, this suggestion may sound crazy, but it might also work. Plus, it's free... :)

Go grab Terragen. Grab the MicroExporter, too. Then, see here: http://www.planetside.co.uk/forums/index.php?topic=12189.0

Basically, you can create a greyscale map of your art, import it into Terragen, manipulate it if yous wish, setting limits and the like, then export it as a .obj file, using the micro-exporter, which you can then load up into just about any 3D package that will, in turn, export it as a .stl file for your 3D printer.

Workflow in 3D environments is crazy... get used to it. :)

Note: If you've used LW, you may be able to get Lightwave to do all of this. Experiment around with getting LW to generate 3D geometry from greyscale maps, if it can do that.