This PowerPoint has several cross sections of everyday objects that have internal layers. It is presented in a way that makes the students guess what the object is. It also generates questions about why there are different layers in these objects, and what the purpose of those layers are. The last slide then presents a picture of the earth with it's internal layers. I use this as an introduction before having the students do a foldable on the Earth's Layers (see Earth's Layers PowerPoint).
(All pictures are taken from the internet, and citations are provided.)