We actively browse the books to see if what we have is possibly in there. In my father's case, the answer is usually 'no', but then again, this is a man who regularly forgets just where in the alphabet a particular letter may appear. Regardless of the family member though, if something we're convinced/hoping is in the book turns out to only exist in our heads, then we will toss the book disdainfully onto the table and utter the mantra, "Huh - stupid book."
Me and Julie have even gone so far as to extend this activity (when it's just the two of us) enough that the other can pick up a puzzle book and have a go at a sudoku or two while we're waiting. All this while listening to a CD.
Sometimes, however, inspiration strikes and we just slap down the tiles, which isn't always a good idea, because The Book is the final arbiter...
I didn't even dare to ask what she was looking for. It was starting to get a little too metaphysical for my taste.