http://idav.ucdavis.edu/~okreylos/ResDev/SARndbox/Movies.html
See the link above. There is a way now to use a model sandbox to create design projects that will show the elevation and contours you create - instantly. From a permaculture standpoint, this would be a dream to play with since moving earth and water around is so essential.
The project in the link doesn't specify, that I heard, how you would be able to go beyond just moving sand around, but I assume if you took the time to create a to-scale sandbox of your, or your clients, property, then you could start demonstrating what your permaculture inspired actions would do.
Or you could just be Sepp Holzter and know damn well what will happen when you make changes to the land.
Anyway, what you will.