terrain deformation

I came up with an idea for a project a while ago. it was a track editor for a racing game. I pretty much gave up because i couldn’t figure out how to do pretty much anything. but as i was browsing the forums, i happened upon the Grid movement thread (http://blenderartists.org/forum/showthread.php?t=176008) and it was exactly what i was looking for. but now i need another answer. is it possible to do real-time terrain deformation with a script like that?