So, earlier I posted a script that lets you (on *nix systems) download and (sort of) automatically install the Minecraft Lojban translation, to get overwritten every update. Well, I have a better solution.
Magic Launcher (available here: http://www.minecraftforum.net/topic/939149-launcher-magic-launcher-100-mods-options-news/) allows you to take any minecraft mod .zip file, and use it with Minecraft without ever modifying the .jar file or deleting anything or getting overwritten.
To use this, simply download the MagicLauncher-1.0.0.exe file and the jbolang.zip file, configure the 'Default' to include the jbolang.zip, launch and set your language in 'Languages' to lojban. You're finished! No more overwritten files, no more hassle.