Hi Alan, if you take a look at the ppt, and open the animation pane and selection pane, you can find out basically how the effect was created. Just replace the pictures and that should be it.
Just to note, I had to import two old animations that are not offered in ppt 2010- Stretch and Collapse. If you click here- http://www.pptalchemy.co.uk/Downloads/Old%20Anims3.msi you will be prompted to download a small file that will restore those old animations to your ppt banner. You may want keep that file as I have found I have to reinstall it each time I open/close ppt.
So, not ideal, but that's the only way I've found to create the page turning effect you saw.
Hope that helps. One last note- this was done in Presenter, not Storyline, so not sure if it will work in Storyline.