Try this displacement map exercise and try one of the double exposure effect tutorials .

Post at least one of each on your web site as Exercise 08.

The instructions say to do a "Save As..." with the Map.psd. Photoshop won't let you do that anymore. Instead do "Save a Copy".

One of the slickest Photoshop tricks ever is to wrap one image around the contours of another. It's great for creating conceptual imagery for ads or artistic purposes. To perform this feat, we'll create a displacement map—a grayscale image that Photoshop uses to warp and bend one image to the curvature of another. 

--Lesa Snider

The instructions below say to do a "Save As..." with the Map.psd. Photoshop won't let you do that anymore. Instead, do "Save a Copy".