A very little known feature of Google+ Is the "auto awesome" feature. I want to sing its praises!
On your smartphone. you can download the G+ application and configure it to automatically back up all your photos to Google+, even if you choose to keep them all private. A useful feature, but not unique.
But dig a little deeper and you will find that you can enable something called "auto-awesome", When you do that the non-evil gnomes at Google will look at all your pictures and from time to time do some crazy fun tweak to it to make it more awesome. And it looks like they add different kinds of awesomeness from time to time.
The beauty here is that this takes literally zero effort on your part: it just happens. And sometimes the creations are just downright.... AWESOME! Here's a before and after to whet your appetite: