It can be very effective to have a picture which periodically (without human intervention) spontaneously changes while the viewer is watching.  Banner ads do this. However, you need not choose to `cycle´ only advertisements: any sequence of graphics can be used.

The Banner Ad properties box (select the Insert menu, and choose Components/Banner Ad Manager) looks like this: As you can see, it is simply a matter of selecting the dimension of the graphic images (they all have to be the same size, unfortunately), choosing a transition effect from those provided, deciding how long each image should show for (again, all images are bound by this setting), and then select however many images you wish.

One other thing - since this "feature" was designed to cater for banner advertisements, you can nominate a URL to jump to when the visitor clicks on the image.