During this holiday season, Google+ is changing some holiday and snow-related photos to become active GIFs with snow falling, bulbs twinkling, etc. If you upload a photo to Google+, they might change it into an active GIF. Update: Google+ is no more so this awesoming service has gone with the wind!
Here, for example, is the book cover for Terry Brooks’ Legends of Shannara: Bearers of the Black Staff. Sort of fun.