Revolving image galleries using CSS animations.
It's really just some trickery. Each image or slide of the gallery has a CSS animation applied to it. The animations are staggered in a way that each image is off screen in some way while the images before it are off screen.
A little. While these offer no controls to skip to the next or previous slide, they can be used to just display a number of images on repeat. I've put it to use on one site already; http://brooklynalpha.org/2011/location