How do I get a glowing line via textures or materials? I've built objects that use the Halo material but it has a vertex glow. How would I make a whole line glow without dividing my surface into an absurdly large number of vertices?
If you want to do this relatively easily and for certain edges, select the appropriate faces in edit mode and click EDIT->Mesh->Faces->Wire Frame on a duplicate of your original model.

Assign new materials with emission. I recommend just doing a solid material and join the models back together (I really usually work in Cycles, and if doing so you can use a simple Emission shader since Blender Internal doesn't really like emitting from materials in my experience). This adds a few vertices, depending on how smooth you want your outlines to be, but I've found that usually they can be pretty simple. You wind up with something like this: