Did a quick search, didn't find. Lock if old, please.
Someone at NeoGAF posted a link to a translated, scanned version of Xenogears Pefect Works. For the unintiated, that's the official artbook filled with TONS of beautiful images and some details about the world of Xenogears, including stuff about the never-released sequels/prequels. (Most, but not all, of it is in-game, albeit buried away in one of the many conversations.) If you love Xenogears, Clicky clicky.
*Calling Naum. Naum to the front thread, please.*