I'm currently working on Gladius, a tactic-rpg from LucasArts for the PS2, GC and XBox.
So far I'm able to change some of the data, like the text seen in the screenshot or values of items and Gladiator classes. I also played a bit around with changing the data of the battles, especially in the multiplayer mode.
My goal is to program more tools for editing this game easier and trying to make a patched/updated version of this too early released game that has some annoying bugs.
Test patches that add some text to the ingame FAQ are already available for PS2 and GC. I'm not working on the XBox version because I have no idea if it has a good emulator to test the changes.