I finished a flash version of my desktop art site,
frontlevel.com. The flash version is meant to "look cool", but not be extremely practical. Its got a fairly long load time thanks to some music and the number of pieces of art that load. I did this entirely to better learn flash and what its capable of doing and to attempt to be creative. I've got 67 desktop wallpapers available for download. Some of them are available in wide-screen resolutions and some will fit your Zune as well.
Take a look at the flash version and let me know what you think.
http://frontlevel.com