"It's a pity I don't own some kind of magical necklace that would make hiding easier. Better crouch behind these rocks!"
The Book: No such scene occurs.
My Opinion: I just wanted to take a minute to talk about how Bilbo Baggins is treated differently in the movies than in the book. The movies have taken efforts to make Bilbo a more competent member of the team; in fact, it'd be fair to say that his given purpose is almost as important as Thorin's, and the rest of the dwarves are really only there to escort him to Erebor (more on that alter, when I talk about the Arkenstone). In the books, Bilbo does not scout ahead of the team, or look around for enemies. Perhaps he might have, if the orcs were in The Hobbit, and then again, maybe not. Bilbo's heroic battle with Azog is a complete fabrication of the movies. He is not this brave or helpful in the books, at least not at this stage of the story.
Personally, I like the change. I think having the burglar scout around for enemies makes sense, and I enjoy seeing Bilbo actually do stuff. Plus, since the "Bilbo finds his courage" character arc happened earlier than Mirkwood in Peter Jackson's version, it doesn't seem like a gross misinterpretation of his character. However, this is just my opinion - there's a lot to be said against the decision to take a main character and completely change his motivations and personality. At this point, in The Hobbit, the eponymous protagonist is still being carried (quite literally) by his companions.