Where could it be?

Our toddler is forever taking things and hiding them throughout our house. He really has no idea what he is doing except that it is fun. Somehow he has gotten his hands on my husband's cell phone and hidden it. We have looked everywhere but it seems to have vanished into thin air. We don't has loss or damage coverage on our phone plan so this is just a bit of a problem since we are locked into a fairly long contract. The price for a replacement phone from our carrier is outrageous. If the phone doesn't turn up soon I think our best option is to look into an unlocked phone that we can have set up for our existing phone contract. Now, if I could only find a similar and simple solution for replacing the library book that he has hidden somewhere.