Heyho,
while translating "The Nutcracker", I found a passage describing "Phantom's Laboratory", which seemed to be a secret room.
I started to look for it and finally found it. I wont tell you where it is though, it was so much fun to find! Please answer the poll whether you have found it or not, but do not post where it is.
-Eike
BTW: Easter Eggs in PPC games and apps rock!