I check out the Bing App every day on my surface just for the amazing photography they feature. One of the smallest yet coolest feature on the surface is ability to make any of these daily pictures your screen lock image! Just swipe up from the bottom in the Bing App and set as image, so neat. You'll note one of the other options when you swipe up is the ability to Save the image...for me its usually hazed out. I've only had the ability to Save one of the images out of the last 20 maybe. Maybe it has to do with copyright issues and where they get the images/whats depicted. It'd be really neat to see rotating lock image options, much like a desktop can rotate through background images.