It's times like these that I wish MS hadn't axed "Active Desktop" from their newer oses.

Back then you could make an html file with one frame or iframe and point it to a website like this or embed a flash stream.

You could just embed this website and have random webcams as background and your icons and everything else would still work normally on top of your new "background".

Eventually the embedded IE would crash and you'd press F5 and it would fix itself.