Random Rotating Images
Random Image Rotation: A List Apart
Create a folder full of images and include the php script above in the folder and you get random rotating images. (Hit the refresh button and the picture below will change.) Now if I can figure out how to make them links that pop up larger versions of the images...
I chose a bunch of photos and exported them with iPhoto using a constraint of 300 x 300 max. In that way all random photos are the same size by either width or height.