Ground fog?

Does anyone know how I could get a good ground fog effect? I'm thinking of maybe a cube set to the height I need the fog, sitting on the ground plane with a shader on it. Ideally the effect could be animated for swirling fog. Any suggestions would be appreciated.

Using the Shade-c framework with the volumetric shader on a model would be a way to get really good looking ground fog >_^

Thanks, yeah I was thinking of something volumetric. I actually just ended up using a modified version of the floor fog in AUM30 and it worked out great.

Maybe Ellos heightfog ?