The only way I know to do this is to have a loop that constantly sets player's transform, and that will be very hacky.
This is one of those things that modders would love to see added into the game.http://forum.blockland.us/index.php?topic=146555.0Maybe, one day, there'll be one huge physics overhaul update that will magically make everything fantastic.
There is a noclip mod.
Bookmark :) this perfect for my ghost bots and players.