I'm trying to apply the wood floor texture from freestuff to the ground plane so that it will show up in a render. At the moment, I have the background set to black and it isn't visible. All I can see in the materials tab to apply the wood floor texture is "Preview". Is it possible to apply the wood texture to a ground plane and use a spotlight to show the texture in just a circular or elliptical pattern?

yes it is possible to do exactly what you want. Have you selected "Display/Guides/groundplane? Also, if you are using spotlights rather than infinite lights you might not be able to see the ground plane if the lights aren't pointing at it. If you need any more help post a screen shot of your settings etc.

Another trick is to apply a transparency map to the ground plane, with only the circular or elliptical part visible.

Thanks! That worked fine. I do have another question, though. I probably should start another thread for this - I have a prop for DAZ's Victoria that eliminates the glow effect in the nostrils (it's from Morphworld 3.0) Does anyone know of a prop that does the same thing for the inside of the mouth?

well the easiest way I know is to select the area in PS and darken it

That's the way I've been doing it so far - I just use the burn tool and magnify the area a lot. But I just wondered if there was a prop for it.