collision detection/artificial gravity

[gyphia]

I would like a function, where when you are in navigator and in walk mode with fixed zoom..instead of passing through terrain..it could just stop moving down and keep to the terrain...literally walking on the surface.  Maybe even have artificial gravity you could turn on or off?..would make for some nice animations. do you think there is a call for this?.
Thanks

[cKleinhuis]

i think this is a mandelbulb3d question, moved it