But as it happens, the flash programming is merely a shiny (and arguably fairly pretty) 'menu' to the various picture at the Flickr tag set for earthwallpapers. Better still, the author uploads daily additions, see today's in 1280x1024 pixels.
Now, I don't really know much about Flickr, but didn't they open some sort of API? Is there a way write a quick Bash, Perl or Python script to have cron download the current picture as a desktop wallpaper?