There are many approaches here, but I'm going to make a recommendation.

Webshots is a free download that gives you controls fit for a king with a choice of top notch photos from a seemingly unlimited supply. They deserve a visit at webshots.com
Now you might think that they have great things but then nothing Masonic.

True, But you can do what I did, I added my favorite Masonic pictures & photos into an album for webshots to use. It was pretty simple, with just a few clicks of the mouse and I was done.

My computer screensaver is now a slide show of Great Masonic Pictures.

Download webshots, its great and its free!