I dunno if anyone here plays first person shooters, but there\'s one called \"Red Faction\" that has destructable environments. The damage to the environment is calculated at the very moment you cause it. I mention this because it would be precisely the system that wouldn\'t work.
However, it might be possible with a set of prefabricated building blocks to add to the environment, or, in the same way, detract. (ie there would be a certain standard sized block you would remove from the ground, or several sizes) On the fly manipulation would be impossible in an MMORPG, I think, but if there was a set of 3d models that every user would already have installed, there\'d be no need to install new models every time the environment was altered.
It would limit the possibilities somewhat, but it might be possible.
Oh, and hi, this being my first post and all.