For those hardcore gamers, there IS a reward for doing just about everything in the game. After you've beaten the game and then beaten Dark Erde Kaiser, talk to the robot in the Robot Academy TWICE to obtain a REAL email address to which you need to send three pieces of information. Your reward for doing so is access to a special section of xenosaga2.com, which contains an image gallery and a 50MB downloadable zip file of PSDs (photoshop documents).

I highly recommend doing this on your own, but if you absolutely MUST know and can't do it yourself, send me a private message and I'll give you the info you need.