You can Use A Vinylmation Figurine as a Disney Autograph Book. Stores at the Disney Parks sell a large Vinylmation doll for around $10. You could pick one up and have the characters autograph it. It would look so cute displayed on your shelf!
Alternatively, you could pick up other autographable items like piggy banks, plaques, pillowcases, etc at your local craft store for characters to sign.
Have a kid that loves dinosaurs? Be sure to visit Build-A-Dino in Downtown Disney.