It randomly picks images from my Flickr or local machine and creates a new desktop image, montage or mosaic every few hours.
JBS is free software with a donation option if you want to support development enabling John to “buy some coffee to stay up late and crank out more features”. It already has many options including support for other web and social media image sources.
Get it from johnsadventures.com/software/backgroundswitcher/
Tenuous Autodesk University Link?
JBS may be sentient, perhaps has a mean sense of humour, as from 10,000+ images it picked a photo from my Autodesk University 2011 Flickr Set and set it to full screen. A view of Las Vegas from the Palazzo Hotel to remind me I’m not at AU 2013!
Of course being Windows 8.1* the Start Menu offers no respite as the same background is seen there!
Although this change seems trivial I’ve found it really improves the Windows 8.1 Start experience. With 8.0 the switch to Start was quite jarring, even disorienting, but that is fixed. It also means JBS goodness can be seen without visiting the desktop which—when using this hybrid in tablet mode—often isn’t necessary.
UPDATE 12/20/2013: JBS got even more awesome, details here