I recently had a couple different clients request that I create a gallery with an image swap. It’s convenient because I could put the functions to use on more than site. I wrote below about how to implement an image swap. Here is an example for expecting mothers.
As you’ll see, the thumbnails are contained in the right-hand column. Click a thumbnail and that image pops up in the main window. I also added a feature so that the text that appears under the main image changes whenever you select a different thumbnail.