Must try this after my Tiger upgrade. bbum is an awesome hack and regularly puts out great stuff like this! Of course I know similar stuff is already available but with this one you get the source.
I updated the Flickr RSS ScreenSaver to actually have a configuration sheet and too allow the RSS feed to be customized from the UI. It is far from perfect.
The groundwork has been laid to handle multiple RSS feeds simultaneously. Currently, the UI -- the Quartz Composer based presentation layer -- needs to b updated to fix the presentation.
Hence, the challenge. I'm out of time on this and, besides, I have the design skills of your average Border Collie.