Jawc-Wallpaper Rotator is a freeware which changes your desktop wallpaper automatically with images from flickr.Also there is another freeware utility called Flickr Wallpaper which downloads the current highlighted picture from Flickr and puts it as the desktop wallpaper.Both these free application use flickr as the image source for changing the desktop wallpaper.
Jawc (Just Another Wallpaper Changer) is a Plugin-Based Wallpaper Changer which changes your desktop background picture from a lot of different sources like your PC’s folders, Flickr or VladStudio.
This software has the option to look for new wallpapers,download wallpapers from flickr and set random images.
The login details of the flickr account should be provided and the wallpaper download destination could be changed.
This Wallaper rotator resides in the system tray and will automatically download images from flickr website at specified time intervals.
Related:Upload photos to flickr automatically
As I said earlier,there is another similar utility called Flickr Wallpaper which does this job but in a different manner.It downloads the current highlighted picture from Flickr and puts it as the desktop wallpaper.
Residing in the system tray this utility will automatically download flickr photos at specified time interval as use it as wallpaper. 
Download these Wallpaper based Flicker tools and enjoy!