I think los is actually talking about how you could take 2 different tileable textures (like, say, grass and mud), then blend them per vertex on geometry... to make a fading boundary between grass and mud or whatever... like what happens when you do terrain editing in UnrealEd... I was also wondering about this too last…
Sounds like you're doing portfolio renders, right los? In that case, you might want to show you're familiar with vertex alpha, and also show a look consistent with the artifacts you get from vert-blending (those luverly linear gradients between verts). fyi, here's how RealityEngine does/did it...…