I’ve had plenty of friends and customers over the years who have used third party programs in order to get their wallpapers to rotate through a “public” gallery periodically throughout the day. I have always hated this since it requires using a 3rd party program (meaning that it is not a part of the O/S or even from Microsoft). I have just discovered, a little late, I might add, that Windows 7 has the ability to use image RSS feeds for updating your wallpaper. I knew Apple had added the RSS feed Wallpapers/Screensavers, but had not seen the wallpaper option.
My personal thoughts about things.