Windows only: Fleace is a Flickr-based desktop switcher for those who only want to switch their desktop wallpaper on startup, or who dislike having wallpaper rotators hang around in their system tray. The stand-alone app can be launched or given a shortcut, which allows the user to preview an image before applying it to the desktop and shutting Fleace down. Alternately, you can add Fleace as a run-once app to your startup process, so it will pull and place Flickr artwork based on tags you specify. Those seeking finer control should check out the excellent