This is actually two different props that make up the entire 'one book' seen on screen. This book is handed to Mike Enslin (John Cusack) during an autograph session, and he then signs it. The first book pictured here is the one he picks up off the table and looks at, which is seen very close-up on screen. Several of these books were made for the production, and each one was distressed by hand (i.e., all the creases on the book were made by physically bending and folding the cover). Thus, every book is different. This one matches up perfectly with the screen shots as seen below.

Screen caps- Notice the creases down the middle...

This second book is the one you see placed on the table by the girl, and is also the one John Cusack actually starts signing on screen. The cover is a little harder to match up, but the white crease at the button center is pretty noticeable. The signature definitely matches up. All of the books I saw (including the one pictured above) had a 'To Ann All the best Mike Enslin' signature in them, but the handwriting and location of the signature were significantly different in each one. I'm guessing each one is from a different take during the actual filming.

Screen caps: