and I know that way doesn’t work
in part because the python code is entirely visible if I open the file [in say, MS notepad], also in part because I can disable running python scripts when the file is loaded or whenever I want [particularly if I use my own build of blender]
a method I haven’t seen used [it probably isn’t worth the effort for anything coming out of blender] is to modify the .blend and your version of blender [with a hex editor if necescary] so that meshes get loaded corrupt, and probably textures too, if not being loaded using your routines.
but, like commercial games, if anyone really cares there is NOTHING you can do for this kind of thing
[but, something like what valve is doing with hl2, namely sending an encrypted 1Gb file prior to release is inheritly a lot more secure because the key and extraction method is not stored in some easily accesable place [they have it, and they are unwilling to give it away until the game comes out]]
once the game comes out, and the key becomes public there WILL be ways to work around the steam authentication that you actually bought the game, there is nothing that can be done
furthermore, some security options have become less feasable with xp service pack 2 [on 64 bit systems with these features] because it disables self modifying code [and buffer overrunns and underrunns], except on a per-application disabled basis