If you are a Tolkien fan, check out: Middle-earth Map II — available on the iTunes App Store.
The Middle-earth Map II is an original “wall sized” map of The World of Arda. Based on the books by J. R. R. Tolkien and Christopher Tolkien, the Middle-earth Map II shows the changes to Arda with the Fall of Beleriand and the rise of Númenor during the Second Age of Middle-earth. See the locations of the Kingdoms in Exile and the founding of Mordor.
When reading the Silmarillion in iBooks, you can switch between the apps (fast app switching - iOS 4.3 — four finger swipe (left or right) for taking notes or visiting other Tolkien reference sites.
I have 2 snaps of the map in my profile album.