Flickr .Net Screensaver
You've put a lot of work into organizing and uploading your pictures to Flickr, so why not take advantage of them on your desktop? Free application Flickr .Net Screensaver displays Flickr images as your screensaver. You can specify which images you'll see based on such criteria as tags, groups, or the user who generated the image. To add a little flair to your desktop wallpaper, try John's Background Switcher, a free app that rotates your desktop wallpaper by pulling photos from Flickr.