After more than a year of using Blender, I finally start to exploit the "blend" texture type. Using a multi-channel material IPO, I can now simulate day-lighting, night illumination, or anywhere in between! Notice how the walls seem to glow with the color of the wood floors--that's the blend texture, not radiosity.
This walkthrough primarily shows the nighttime illumination settings, though the exterior image of the building uses the daytime illumination settings.